Resist composition, method for forming resist pattern, and polymer

Abstract

The present invention employs a resist composition containing a resin component which exhibits changed solubility in a developing solution under the action of an acid. The resin component contains a polymer in which a linking group represented by general formula (a0-L) constitutes a portion of the main chain of the polymer. In formula (a0-L), R10 represents a hydrocarbon group in which a linking group is divided into two groups by the action of an acid. R20 and R30 are each independently a C1-5 alkylene group. *1 and *2 each represent a dangling bond that bonds to the main chain of the polymer. O is an oxygen atom. S is a sulfur atom. Using this resist composition in the formation of a resist pattern, high sensitivity can be achieved, lithography characteristics such as roughness reduction can be enhanced, and film loss can be further suppressed.

Description

Resist composition, method for forming a resist pattern, and polymer

[0001] The present invention relates to a resist composition, a resist pattern formation method, and a polymer. This application claims priority under Japanese Patent Application No. 2024-227362, filed in Japan on December 24, 2024, the contents of which are incorporated herein by reference.

[0002] In recent years, advances in lithography technology have led to rapid miniaturization of patterns in the manufacturing of semiconductor devices and liquid crystal display elements. Generally, miniaturization is achieved by shortening the wavelength (increasing the energy) of the exposure light source.

[0003] Resist materials are required to possess lithography characteristics such as sensitivity to these exposure light sources and resolution capable of reproducing patterns of fine dimensions. Conventionally, chemically amplified resist compositions have been used as resist materials that satisfy these requirements, containing a base component whose solubility in a developer solution changes due to the action of an acid, and an acid generator component that generates acid upon exposure. In chemically amplified resist compositions, polymer compounds having multiple constituent units are generally used as the base component to improve lithography characteristics and other properties.

[0004] The polymer compounds used in the aforementioned base components are typically produced by radical polymerization of monomers having various functions. Azo polymerization initiators such as azobisisobutyronitrile (AIBN) are generally used as polymerization initiators in radical polymerization, and a partial structure of the azo polymerization initiator is introduced at the ends of the produced polymer compounds. Polymer compounds in which an acid-dissociable group is introduced at the main chain end as the partial structure, and resist compositions containing the same have been disclosed (see, for example, Patent Document 1).

[0005] Japanese Patent Publication No. 2014-153686

[0006] As resist patterns become smaller, for example, in EUV (extreme ultraviolet) and EB (electron beam) lithography, the goal is to form fine patterns of several tens of nanometers. With this miniaturization of resist patterns, the challenge is to improve lithographic characteristics such as roughness reduction while maintaining good sensitivity. However, these lithographic characteristics are in a trade-off relationship, and improving one characteristic tends to degrade the other. In addition, with the miniaturization of resist patterns, development loss (film thinning) can become a problem during development, as the unexposed parts of the resist film dissolve excessively in the developer.

[0007] The present invention has been made in view of the above circumstances, and aims to provide a resist composition that can be made more sensitive in the formation of a resist pattern, improve lithography characteristics such as roughness reduction, and further suppress film loss, and a polymer suitable for use with the resist composition.

[0008] To solve the above problems, the present invention employs the following configuration. That is, the first aspect of the present invention is a resist composition that generates acid upon exposure and whose solubility in a developer changes due to the action of the acid, the resist composition containing a resin component (A1) whose solubility in a developer changes due to the action of the acid, wherein the resin component (A1) contains a polymer (A1-0) in which a linking group represented by the following general formula (a0-L) constitutes part of the polymer main chain.

[0009] [In the formula, R １０ R represents a hydrocarbon group whose linking group is split into two by the action of an acid. ２０ and R ３０ *1 and *2 each independently represent alkylene groups with 1 to 5 carbon atoms. *1 and *2 each represent bonds attached to the polymer main chain. O is an oxygen atom. S is a sulfur atom.

[0010] A second aspect of the present invention is a resist pattern forming method comprising the steps of forming a resist film on a support using a resist composition according to the first aspect, exposing the resist film, and developing the exposed resist film to form a resist pattern.

[0011] A third aspect of the present invention is a polymer in which a linking group represented by the following general formula (a0-L) constitutes a part of the polymer main chain.

[0012] [In the formula, R １０ R represents a hydrocarbon group whose linking group is split into two by the action of an acid. ２０ and R ３０ *1 and *2 each independently represent alkylene groups with 1 to 5 carbon atoms. *1 and *2 each represent bonds attached to the polymer main chain. O is an oxygen atom. S is a sulfur atom.

[0013] According to the present invention, it is possible to provide a resist composition that can be made more sensitive in the formation of a resist pattern, improve lithography characteristics such as roughness reduction, and further suppress film loss, as well as a polymer suitable for use with the resist composition.

[0014] In this specification and in these claims, “aliphatic” is defined as a concept relative to aromatic, meaning a group, compound, etc. that does not possess aromaticity. Unless otherwise specified, “alkyl group” includes linear, branched, and cyclic monovalent saturated hydrocarbon groups. The same applies to alkyl groups in alkoxy groups. Unless otherwise specified, “alkylene group” includes linear, branched, and cyclic divalent saturated hydrocarbon groups. “Halogen atom” includes fluorine, chlorine, bromine, and iodine atoms. “Constituent unit” means a monomer unit (monomer unit) that constitutes a polymer compound (resin, polymer, copolymer). When it is stated that “may have substituents,” this refers to the substitution of a hydrogen atom (-H) with a monovalent group, or a methylene group (-CH ２ This includes both cases where the negative (-) is substituted with a divalent group. "Exposure" is a concept that includes all forms of radiation irradiation.

[0015] An "acid-degradable group" is a group that is acid-degradable, meaning that at least some of the bonds in its structure can be cleaved by the action of an acid. Examples of acid-degradable groups whose polarity increases by the action of an acid include groups that decompose to produce polar groups by the action of an acid. Examples of polar groups include carboxyl groups, hydroxyl groups, amino groups, and sulfo groups (-SO4). ３ Examples include H). More specifically, examples of acid-degradable groups include groups in which the polar group is protected by an acid-dissociable group (for example, a group in which the hydrogen atom of an OH-containing polar group is protected by an acid-dissociable group).

[0016] An "acid-dissociable group" refers to both (i) a group that has acid-dissociability, in which the bond between the acid-dissociable group and an adjacent atom can be cleaved by the action of an acid, and (ii) a group in which, after some of the bonds are cleaved by the action of an acid, a decarboxylation reaction occurs, further cleaving of the bond between the acid-dissociable group and an adjacent atom. The acid-dissociable group constituting the acid-degradable group must be a group with lower polarity than the polar group generated by the dissociation of the acid-dissociable group. As a result, when the acid-dissociable group dissociates by the action of an acid, a polar group with higher polarity than the acid-dissociable group is generated, increasing the polarity. Consequently, the overall polarity of component (A1) increases. This increase in polarity relatively changes the solubility in the developer; solubility increases when the developer is an alkaline developer, and decreases when the developer is an organic developer.

[0017] "Base material components" are organic compounds that have film-forming ability. Organic compounds used as base material components are broadly classified into nonpolymers and polymers. Nonpolymers typically have a molecular weight of 500 or more and less than 4000 (hereinafter referred to as "low molecular weight compounds"). Hereinafter, when "resins," "high molecular weight compounds," or "polymers" are used, polymers with a molecular weight of 1000 or more are referred to. For polymers, the weight-average molecular weight in terms of polystyrene obtained by GPC (gel permeation chromatography) shall be used as the molecular weight.

[0018] The term "induced structural unit" means a structural unit formed by the cleavage of a multiple bond between carbon atoms, for example, an ethylenic double bond. The "acrylic ester" may have a hydrogen atom bonded to the carbon atom at the α-position substituted with a substituent. The substituent (R αｘ ) is an atom or group other than a hydrogen atom. Also, it is intended to include diesters of itaconic acid in which the substituent (R αｘ ) is substituted with a substituent containing an ester bond, and α-hydroxyacrylic esters in which the substituent (R αｘ ) is substituted with a hydroxyalkyl group or a group obtained by modifying its hydroxyl group. Unless otherwise specified, the carbon atom at the α-position of the acrylic ester refers to the carbon atom to which the carbonyl group of acrylic acid is bonded. Hereinafter, an acrylic ester in which the hydrogen atom bonded to the carbon atom at the α-position is substituted with a substituent may be referred to as an α-substituted acrylic ester.

[0019] The term "derivative" is a concept that includes those in which the hydrogen atom at the α-position of the target compound is substituted with another substituent such as an alkyl group or a halogenated alkyl group, and derivatives thereof. Examples of such derivatives include those in which the hydrogen atom of the hydroxyl group of the target compound in which the hydrogen atom at the α-position may be substituted with a substituent is substituted with an organic group; those in which a substituent other than a hydroxyl group is bonded to the target compound in which the hydrogen atom at the α-position may be substituted with a substituent, and the like. Unless otherwise specified, the α-position refers to the first carbon atom adjacent to the functional group. Examples of the substituent that substitutes the hydrogen atom at the α-position of hydroxystyrene include those similar to R αｘ .

[0020] In this specification and the scope of the claims, depending on the structure represented by the chemical formula, there may be an asymmetric carbon, and enantiomers or diastereoisomers may exist. In that case, those isomers are represented by one chemical formula. Those isomers may be used alone or as a mixture.

[0021] (Resist Composition) One embodiment of the resist composition according to the first aspect is one which generates acid upon exposure and whose solubility in a developer changes due to the action of the acid. Such a resist composition contains a base component (A) (hereinafter also referred to as "component (A)") whose solubility in a developer changes due to the action of the acid. Component (A) contains a resin component (A1) (hereinafter also referred to as "component (A1)") whose solubility in a developer changes due to the action of the acid, and component (A1) contains a polymer in which a linking group that is divided into two by the action of the acid constitutes part of the polymer main chain.

[0022] In the resist composition of this embodiment, component (A) may generate acid upon exposure, or an additive component formulated separately from component (A) may generate acid upon exposure. Specifically, the resist composition of this embodiment may further contain (1) an acid-generating agent component that generates acid upon exposure; (2) component (A) may be a component that generates acid upon exposure; or (3) component (A) may be a component that generates acid upon exposure and further contains an acid-generating agent component. That is, in the cases of (2) and (3) above, component (A) is a "base component that generates acid upon exposure and whose solubility in the developer solution changes due to the action of the acid." When component (A) is a base component that generates acid upon exposure and whose solubility in the developer solution changes due to the action of the acid, it is preferable that the polymer generates acid upon exposure and whose solubility in the developer solution changes due to the action of the acid. As such a polymer, a copolymer having constituent units that generate acid upon exposure can be used. The constituent units that generate acid upon exposure can be the constituent units (a5) and (a6) described later.

[0023] When a resist film is formed using the resist composition of this embodiment and selective exposure is performed on the resist film, for example, acid is generated from the acid generator component in the exposed areas of the resist film, and the solubility of component (A) in the developer changes due to the action of the acid, while the solubility of component (A) in the developer does not change in the unexposed areas of the resist film. As a result, a difference in solubility in the developer occurs between the exposed and unexposed areas of the resist film. Therefore, when the resist film is developed, if the resist composition is positive type, the exposed areas of the resist film are dissolved and removed to form a positive type resist pattern, and if the resist composition is negative type, the unexposed areas of the resist film are dissolved and removed to form a negative type resist pattern.

[0024] The resist composition of this embodiment may be a positive-type resist composition or a negative-type resist composition. Furthermore, the resist composition of this embodiment may be for an alkaline development process that uses an alkaline developer for the development process during resist pattern formation, or for a solvent development process that uses a developer containing an organic solvent (organic developer) for the development process.

[0025] <Substrate Component (A)> In the resist composition of this embodiment, component (A) includes at least the resin component (A1). That is, component (A) includes at least a resin component containing a polymer whose solubility in the developer changes due to the action of an acid, and in which a linking group represented by the general formula (a0-L) constitutes part of the polymer main chain. By using such a component (A1), the polarity of the substrate component changes before and after exposure, so that good development contrast can be obtained not only in the alkaline development process but also in the solvent development process. In addition, in the formation of the resist pattern, lithography characteristics such as sensitivity and roughness reduction, as well as the effect of suppressing film thinning, can all be improved. As component (A), at least one of other polymer compounds and low molecular weight compounds may be used in combination with component (A1). The proportion of component (A1) in component (A) is preferably 25% by mass or more, more preferably 50% by mass or more, even more preferably 75% by mass or more, and may be 100% by mass, based on the total mass of component (A). When the proportion is 25% by mass or more, the above-mentioned effects, good lithography characteristics, and resist pattern shape are more likely to be obtained.

[0026] ・Regarding component (A1) Component (A1) is a resin component whose solubility in the developer changes due to the action of an acid. In addition, component (A1) includes a polymer in which a linking group represented by the general formula (a0-L) described later constitutes part of the polymer main chain (hereinafter also referred to as "component (A1-0)"). In the resist composition of this embodiment, component (A1) may consist only of component (A1-0), or it may be a combination of component (A1-0) and a polymer whose solubility in the developer changes due to the action of an acid (excluding those corresponding to component (A1-0); hereinafter also referred to as "component (A1-1)").

[0027] ...Regarding component (A1-0) Component (A1-0) is a polymer (A1-0) in which a linking group represented by the following general formula (a0-L) constitutes a part of the polymer main chain. Preferably, this (A1-0) component is a polymer compound in which a first copolymer is bonded to the bond side *1 and a second copolymer is bonded to the bond side *2 via the linking group. Preferably, the first copolymer and the second copolymer each have a constituent unit (a1) that contains an acid-degradable group whose polarity increases with the action of an acid. In addition, the first copolymer and the second copolymer each may have other constituent units as needed in addition to the constituent unit (a1).

[0028] [In the formula, R １０ R represents a hydrocarbon group whose linking group is split into two by the action of an acid. ２０ and R ３０ *1 and *2 each independently represent alkylene groups with 1 to 5 carbon atoms. *1 and *2 each represent bonds attached to the polymer main chain. O is an oxygen atom. S is a sulfur atom.

[0029] In the above formula (a0 - L), R １０ R represents a hydrocarbon group whose linking group is split into two by the action of an acid. １０ In this context, "the linking group is separated into two by the action of the acid" means that R １０ And, R １０ The bond between at least one oxygen atom adjacent to and is broken, or R １０ Some of the bonds forming the polymer (A1-0) are cleaved, and the polymer (A1-0) becomes *1-S-R ２０ A polymerization region having -C(=O)-O- at the main chain end, and -O-C(=O)-R ３０ This means that it separates into a polymerization region having -S-*2 at the end of the main chain and another region.

[0030] R １０ The hydrocarbon group in (x) is an acid-dissociable hydrocarbon group in which the bond between the hydrocarbon group and the oxygen atom adjacent to the hydrocarbon group can be cleaved by the action of an acid. Alternatively, R １０The hydrocarbon groups in (y) include acid-degradable groups in which at least some of the bonds in the structure of the hydrocarbon group can be cleaved by the action of an acid, causing the hydrocarbon group itself to decompose. Among these, R is selected from the viewpoint of sensitivity and solubility in the developer. １０ The hydrocarbon group in is preferably (x) as described above.

[0031] In the above general formula (a0-L), R １０ Preferably, the hydrocarbon group is one in which at least one carbon atom (C*) bonded to -C(=O)-O- is a tertiary carbon atom, or a hydrocarbon group in which the carbon atom (C*) is a secondary carbon atom.

[0032] If the carbon atom (C*) is a tertiary carbon atom, R １０ It is more preferable that the hydrocarbon group consists of two carbon atoms (C*) bonded to the -O- in the -C(=O)-O- on both sides, and both are tertiary carbon atoms.

[0033] If the carbon atom (C*) is a secondary carbon atom, then R １０ It is more preferable that the hydrocarbon group is such that both carbon atoms (C*) bonded to the -O- in the -C(=O)-O- on both sides are secondary carbon atoms. Alternatively, if the carbon atoms (C*) are secondary carbon atoms, R １０ It is more preferable that the α and β positions of the carbon atom (C*) are hydrocarbon groups that form a carbon-carbon unsaturated bond.

[0034] Preferred R １０ The following general formula (R １０ Examples of hydrocarbon groups represented by -r include:

[0035] [In the formula, R １０１ R is a chain-like or cyclic hydrocarbon group. １０２ ~R １０５ Each of these is independently a linear or branched alkyl group, a linear or cyclic alkenyl group, a linear alkynyl group, a cyclic hydrocarbon group, or a hydrogen atom. However, R １０２ and R １０４ It does not simultaneously become a hydrogen atom. R １０３ and R１０５ It does not simultaneously become a hydrogen atom. R １０４ and R １０５ These elements may combine with each other to form a ring. １０１ and R １０２ These may combine with each other to form a ring. The ** at both ends represent bonding hands that connect with -O- in -C(=O)-O-.

[0036] The above formula (R １０ -r) Medium, R １０１ In this, the chain-like hydrocarbon group may be saturated or unsaturated, and may be linear or branched. The linear saturated hydrocarbon group preferably has 1 to 10 carbon atoms, more preferably 1 to 8, even more preferably 1 to 5, particularly preferably 1 to 3, and most preferably 1 to 2. As the linear saturated hydrocarbon group, a linear alkylene group is preferred, specifically a methylene group [-CH] ２ -], ethylene group [- (CH ２ ) ２ -], trimethylene group [-(CH ２ ) ３ -], tetramethylene group [-(CH ２ ) ４ -], pentamethylene group [-(CH ２ ) ５ Examples include -]. The branched saturated hydrocarbon group preferably has 2 to 10 carbon atoms, more preferably 2 to 8, even more preferably 3 to 5, and most preferably 3. A branched alkylene group is preferred as the branched saturated hydrocarbon group, specifically -CH(CH ３ )-,-CH(CH ２ CH ３ )-,-C(CH ３ ) ２ -, -C(CH ３ ) (CH ２ CH ３ )-,-C(CH ３ ) (CH ２ CH ２ CH ３ )-,-C(CH ２ CH ３ ) ２ - Alkyl methylene groups such as -CH(CH３ ), CH ２ -, -CH(CH ３ ), CH(CH ３ ), -C(CH ３ ), ２ CH ２ -, -CH(CH ２ CH ３ ), CH ２ -, -C(CH ２ CH ３ ), ２ -CH ２ - and other alkylethylene groups; -CH(CH ３ ), CH ２ CH ２ -, -CH ２ CH(CH ３ ), CH ２ - and other alkyltrimethylene groups; -CH(CH ３ ), CH ２ CH ２ ]>CH ２ -, -CH ２ CH(CH ３ ), CH ２ CH ２ - and other alkyltetramethylene groups and other alkylalkylene groups. The alkyl group in the alkylalkylene group is preferably a linear alkyl group having 1 to 5 carbon atoms.

[0037] R １０１ The unsaturated hydrocarbon group in may be, for example, an alkenylene group or an alkynylene group. Examples of the alkenylene group include alkenylene groups having 2 to 4 carbon atoms, which may be linear or branched. Examples of the linear alkenylene group having 2 to 4 carbon atoms include an ethenylene group (vinylene group), 1-propenylene group, 2-propenylene group, and butynylene group. Examples of the branched alkenylene group having 3 or 4 carbon atoms include 1-methylvinylene group, 1-methylpropenylene group, and 2-methylpropenylene group. Examples of the alkynylene group include alkynylene groups having 2 to 4 carbon atoms, such as an ethynylene group (-C≡C-).

[0038] R １０１In this context, the cyclic hydrocarbon group may be a cyclic aliphatic hydrocarbon group or an aromatic hydrocarbon group. Examples of cyclic aliphatic hydrocarbon groups include a group obtained by removing two hydrogen atoms from an aliphatic hydrocarbon ring, and a group in which the aliphatic hydrocarbon ring is interposed in the middle of a chain of aliphatic hydrocarbon groups. The cyclic aliphatic hydrocarbon group preferably has 3 to 20 carbon atoms, and more preferably 3 to 12 carbon atoms. The cyclic aliphatic hydrocarbon group may be a polycyclic group or a monocyclic group. As a monocyclic group, a group obtained by removing two hydrogen atoms from a monocycloalkane having 3 to 6 carbon atoms is preferred, and examples of such monocycloalkanes include cyclopentane and cyclohexane. As a polycyclic group, a group obtained by removing two hydrogen atoms from a polycycloalkane having 7 to 12 carbon atoms is preferred, and specific examples of such polycycloalkanes include adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane. The cyclic aliphatic hydrocarbon group may have substituents such as alkyl groups having 1 to 5 carbon atoms.

[0039] R １０１In this context, the aromatic hydrocarbon group is a divalent hydrocarbon group having at least one aromatic ring. This aromatic ring is not particularly limited as long as it is a cyclic conjugated system having 4n+2 π electrons, and may be monocyclic or polycyclic. The number of carbon atoms in the aromatic ring is preferably 5 to 30, more preferably 5 to 20, even more preferably 6 to 15, and particularly preferably 6 to 12. However, this number of carbon atoms does not include the number of carbon atoms in substituents. Specific examples of aromatic rings include aromatic hydrocarbon rings such as benzene, naphthalene, anthracene, and phenanthrene. Specific examples of aromatic hydrocarbon groups include groups obtained by removing two hydrogen atoms from the aromatic hydrocarbon ring (arylene groups); groups obtained by removing two hydrogen atoms from aromatic compounds containing two or more aromatic rings (e.g., biphenyl, fluorene, etc.); and groups in which one hydrogen atom of an aryl group obtained by removing one hydrogen atom from the aromatic hydrocarbon ring (aryl groups) is substituted with an alkylene group (for example, groups obtained by removing one more hydrogen atom from the aryl group in arylalkyl groups such as benzyl, phenethyl, 1-naphthylmethyl, 2-naphthylmethyl, 1-naphthylethyl, and 2-naphthylethyl groups). Aromatic hydrocarbon groups may have substituents such as alkyl groups having 1 to 5 carbon atoms.

[0040] The above formula (R １０ -r) Medium, R １０２ ~R １０５ Each of these is independently a linear or branched alkyl group, a linear or cyclic alkenyl group, a linear alkynyl group, a cyclic hydrocarbon group, or a hydrogen atom.

[0041] Linear or branched alkyl groups: R １０２ ~R １０５ In this, the linear alkyl group preferably has 1 to 5 carbon atoms, more preferably 1 to 4 carbon atoms, and even more preferably 1 or 2 carbon atoms. Specifically, examples include methyl group, ethyl group, n-propyl group, n-butyl group, n-pentyl group, etc. Among these, methyl group, ethyl group, and n-butyl group are preferred, and methyl group and ethyl group are more preferred. １０２ ~R １０５In this, the branched alkyl group preferably has 3 to 10 carbon atoms, and more preferably 3 to 5 carbon atoms. Specifically, examples include isopropyl group, isobutyl group, tert-butyl group, isopentyl group, neopentyl group, 1,1-diethylpropyl group, 2,2-dimethylbutyl group, etc., with isopropyl group being preferred.

[0042] Chain-like or cyclic alkenyl group: R １０２ ~R １０５ In this context, the linear or cyclic alkenyl group is preferably an alkenyl group having 2 to 10 carbon atoms. The linear alkenyl group may be linear or branched, preferably having 2 to 10 carbon atoms, more preferably 2 to 5 carbon atoms, and even more preferably 2 to 4 carbon atoms. Examples of linear alkenyl groups include vinyl groups, propenyl groups (allyl groups), and butenyl groups. Examples of branched alkenyl groups include 1-methylvinyl groups, 2-methylvinyl groups, 1-methylpropenyl groups, and 2-methylpropenyl groups.

[0043] Chain-like alkynyl group: R １０２ ~R １０５ Specific examples of linear alkynyl groups include linear alkynyl groups such as ethynyl group, propargyl group, and 3-pentynyl group; and branched alkynyl groups such as 1-methylpropargyl group.

[0044] Cyclic hydrocarbon group: R １０２ ~R １０５In this context, the cyclic hydrocarbon group may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group, and may be a polycyclic or monocyclic group. As a monocyclic aliphatic hydrocarbon group, a group obtained by removing one hydrogen atom from a monocycloalkane is preferred. The monocycloalkane is preferably one having 3 to 6 carbon atoms, specifically cyclopentane, cyclohexane, etc. As a polycyclic aliphatic hydrocarbon group, a group obtained by removing one hydrogen atom from a polycycloalkane is preferred, and the polycycloalkane is preferably one having 7 to 12 carbon atoms, specifically adamantane, norbornane, isobornane, tricyclo[5.2.1.0 ２，６ Examples include decane and tetracyclododecane.

[0045] R １０２ ~R １０５ In this context, the aromatic hydrocarbon group is a hydrocarbon group having at least one aromatic ring. This aromatic ring is not particularly limited as long as it is a cyclic conjugated system having 4n+2 π electrons, and may be monocyclic or polycyclic. The number of carbon atoms in the aromatic ring is preferably 5 to 30, more preferably 5 to 20, even more preferably 6 to 15, and particularly preferably 6 to 12. Specific examples of aromatic rings include aromatic hydrocarbon rings such as benzene, naphthalene, anthracene, and phenanthrene. Specifically, examples of this aromatic hydrocarbon group include: a group obtained by removing one hydrogen atom from the aromatic hydrocarbon ring (aryl group); a group obtained by removing one hydrogen atom from an aromatic compound containing two or more aromatic rings (e.g., biphenyl, fluorene, etc.); and a group in which one of the hydrogen atoms of the aromatic hydrocarbon ring is substituted with an alkylene group (e.g., arylalkyl groups such as benzyl group, phenethyl group, 1-naphthylmethyl group, 2-naphthylmethyl group, 1-naphthylethyl group, 2-naphthylethyl group, etc.). The number of carbon atoms in the alkylene group bonded to the aromatic hydrocarbon ring is preferably 1 to 4, more preferably 1 to 2, and particularly preferably 1.

[0046] The above formula (R １０ -r) Medium, R １０４ and R １０５These may be joined together to form a ring. The above formula (R １０ -r) Medium, R １０１ and R １０２ These groups may bond with each other to form a ring. Examples of these ring structures include groups obtained by removing two hydrogen atoms from an aliphatic hydrocarbon ring. The aliphatic hydrocarbon ring preferably has 3 to 20 carbon atoms, and more preferably 3 to 12 carbon atoms. The group obtained by removing two hydrogen atoms from an aliphatic hydrocarbon ring may be a saturated aliphatic hydrocarbon ring, an unsaturated aliphatic hydrocarbon ring, a polycyclic group, or a monocyclic group. As monocyclic groups, groups obtained by removing two hydrogen atoms from a monocycloalkane or monocycloalkene with 3 to 6 carbon atoms are preferred, such as cyclopentane, cyclohexane, cyclopentene, and cyclohexene. As polycyclic groups, groups obtained by removing two hydrogen atoms from a polycycloalkane with 7 to 12 carbon atoms are preferred, and specific examples of such polycycloalkanes include adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane. The aliphatic hydrocarbon ring may have substituents such as alkyl groups with 1 to 5 carbon atoms.

[0047] A more favorable R １０ As the above general formula (R １０ -r) In R １０１ However, it is a chain-like hydrocarbon group, R １０２ and R １０３ Each of these is a linear or branched alkyl group, a linear alkenyl group, or an aromatic hydrocarbon group, R １０４ and R １０５ Examples include hydrocarbon groups (where both carbon atoms (C*) are tertiary carbon atoms) in which R is bonded to each other to form an aliphatic hydrocarbon ring (monocyclic group). １０ Specific examples are shown below.

[0048]

[0049] Alternatively, a more preferable R １０ As the above general formula (R １０ -r) In R １０１However, the α and β positions of the carbon atom (C*) form a carbon-carbon unsaturated bond, and R １０２ and R １０３ Each of these is a hydrogen atom, R １０４ and R １０５ Examples include hydrocarbon groups (where both carbon atoms (C*) are secondary carbon atoms) in which R is bonded to each other to form an unsaturated aliphatic hydrocarbon ring (monocyclic group). １０ Specific examples are shown below.

[0050]

[0051] In the above formula (a0 - L), R ２０ and R ３０ Each of these independently represents an alkylene group with 1 to 5 carbon atoms. ２０ and R ３０ The alkylene groups in each may be linear or branched, and are preferably alkylene groups having 1 to 3 carbon atoms, and a methylene group [-CH ２ -], ethylene group [- (CH ２ ) ２ It is more preferable that it be a -, and particularly preferable that it be a methylene group.

[0052] In the above formula (a0-L), *1 and *2 represent bonds attached to the polymer main chain, respectively. O is an oxygen atom. S is a sulfur atom.

[0053] The following are specific examples of linking groups represented by the general formula (a0-L). The brackets [] in the formula indicate that it is part of the polymer main chain structure.

[0054]

[0055]

[0056]

[0057]

[0058] The linking group represented by the general formula (a0-L) is preferably selected from the group consisting of the linking groups represented by the above chemical formulas (a0-L-1) to (a0-L-7), the linking groups represented by the above chemical formulas (a0-L-11) to (a0-L-13), the linking groups represented by the above chemical formulas (a0-L-14) to (a0-L-19), and the linking group represented by the chemical formula (a0-L-21). In the formation of a resist pattern, from the viewpoint of achieving both high sensitivity and roughness reduction, it is more preferable to select from the group consisting of the linking groups represented by the above chemical formulas (a0-L-1) to (a0-L-3), the linking groups represented by the above chemical formulas (a0-L-5) to (a0-L-7), and the linking groups represented by the above chemical formulas (a0-L-11) to (a0-L-13).

[0059] The (A1-0) component may be any polymer in which the linking group represented by the general formula (a0-L) above constitutes a part of the polymer main chain, and the structure other than the linking group may be the same as that of a resin component (base resin) that is usually used as a substrate component for chemically amplified resists. The (A1-0) component is preferably a polymer compound in which a first copolymer is bonded to the bond side *1 and a second copolymer is bonded to the bond side *2 via the linking group. The first copolymer and the second copolymer each preferably have a constituent unit (a1) that contains an acid-degradable group whose polarity increases with the action of an acid. In addition, the first copolymer and the second copolymer each may also have other constituent units in addition to the constituent unit (a1).

[0060] <<Constituent Unit (a1)>> Constituent unit (a1) is a constituent unit that contains an acid-degradable group whose polarity increases due to the action of an acid. Component (A1-0) preferably has constituent unit (a1).

[0061] Examples of acid-dissociable groups include those previously proposed as acid-dissociable groups for base resins used in chemically amplified resist compositions. Specifically, examples of acid-dissociable groups proposed for base resins used in chemically amplified resist compositions include the following: "acetal-type acid-dissociable groups," "tertiary alkyl ester-type acid-dissociable groups," "tertiary alkyloxycarbonyl acid-dissociable groups," and "secondary alkyloxycarbonyl acid-dissociable groups."

[0062] Acetal-type acid-dissociating group: Among the polar groups, an example of an acid-dissociating group that protects a carboxyl group or a hydroxyl group is the acid-dissociating group represented by the following general formula (a1-r-1) (hereinafter sometimes referred to as an "acetal-type acid-dissociating group").

[0063] [In the formula, Ra' １ , Ra' ２ Ra' is a hydrogen atom or an alkyl group. ３ is a hydrocarbon group, Ra' ３ Ra' １ , Ra' ２ It may combine with any of the following to form a ring.

[0064] In formula (a1-r-1), Ra' １ and Ra' ２ Preferably, at least one of them is a hydrogen atom, and more preferably, both are hydrogen atoms. １ Or Ra' ２ If the alkyl group is an alkyl group having 1 to 5 carbon atoms, then an alkyl group having 1 to 5 carbon atoms is preferred. Specifically, linear or branched alkyl groups are preferred. More specifically, examples include methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, isobutyl group, tert-butyl group, pentyl group, isopentyl group, neopentyl group, etc., with methyl group or ethyl group being more preferred, and methyl group being particularly preferred.

[0065] In formula (a1-r-1), Ra' ３Examples of hydrocarbon groups include linear or branched alkyl groups, or cyclic hydrocarbon groups. The linear alkyl group preferably has 1 to 5 carbon atoms, more preferably 1 to 4 carbon atoms, and even more preferably 1 or 2 carbon atoms. Specifically, examples include methyl groups, ethyl groups, n-propyl groups, n-butyl groups, and n-pentyl groups. Among these, methyl groups, ethyl groups, or n-butyl groups are preferred, and methyl groups or ethyl groups are more preferred.

[0066] The branched alkyl group preferably has 3 to 10 carbon atoms, and more preferably 3 to 5 carbon atoms. Specifically, examples include isopropyl group, isobutyl group, tert-butyl group, isopentyl group, neopentyl group, 1,1-diethylpropyl group, 2,2-dimethylbutyl group, etc., with isopropyl group being preferred.

[0067] Ra' ３ When the hydrocarbon group is cyclic, it may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group, and may be a polycyclic or monocyclic group. As a monocyclic aliphatic hydrocarbon group, a group obtained by removing one hydrogen atom from a monocycloalkane is preferred. The monocycloalkane is preferably one having 3 to 6 carbon atoms, specifically cyclopentane, cyclohexane, etc. As a polycyclic aliphatic hydrocarbon group, a group obtained by removing one hydrogen atom from a polycycloalkane is preferred, and the polycycloalkane is preferably one having 7 to 12 carbon atoms, specifically adamantane, norbornane, isobornane, tricyclo[5.2.1.0 ２，６ Examples include decane and tetracyclododecane.

[0068] Ra' ３When a cyclic hydrocarbon group becomes an aromatic hydrocarbon group, the aromatic hydrocarbon group is a hydrocarbon group having at least one aromatic ring. This aromatic ring is not particularly limited as long as it is a cyclic conjugated system having 4n+2 π electrons, and may be monocyclic or polycyclic. The number of carbon atoms in the aromatic ring is preferably 5 to 30, more preferably 5 to 20, even more preferably 6 to 15, and particularly preferably 6 to 12. Specific examples of aromatic rings include aromatic hydrocarbon rings such as benzene, naphthalene, anthracene, and phenanthrene; and aromatic heterocycles in which some of the carbon atoms constituting the aromatic hydrocarbon ring are substituted with heteroatoms. Examples of heteroatoms in aromatic heterocycles include oxygen atoms, sulfur atoms, and nitrogen atoms. Specific examples of aromatic heterocycles include pyridine rings and thiophene rings. ３ Specific examples of aromatic hydrocarbon groups in this context include: a group obtained by removing one hydrogen atom from the aromatic hydrocarbon ring or aromatic heterocycle (aryl group or heteroaryl group); a group obtained by removing one hydrogen atom from an aromatic compound containing two or more aromatic rings (e.g., biphenyl, fluorene, etc.); and a group in which one of the hydrogen atoms of the aromatic hydrocarbon ring or aromatic heterocycle is substituted with an alkylene group (e.g., arylalkyl groups such as benzyl group, phenethyl group, 1-naphthylmethyl group, 2-naphthylmethyl group, 1-naphthylethyl group, 2-naphthylethyl group, etc.). The number of carbon atoms in the alkylene group bonded to the aromatic hydrocarbon ring or aromatic heterocycle is preferably 1 to 4, more preferably 1 to 2, and particularly preferably 1.

[0069] Ra' ３ The cyclic hydrocarbon group in may have substituents. Examples of substituents include -R Ｐ１ , -R Ｐ２ -O-R Ｐ１ , -R Ｐ２ -CO-R Ｐ１ , -R Ｐ２ -CO-OR Ｐ１ , -R Ｐ２ -O-CO-R Ｐ１ , -R Ｐ２ -OH, -R Ｐ２ -CN or -RＰ２ -COOH (These substituents are collectively referred to as "Ra ｘ５ It is also called "." ) are some examples. Here, R Ｐ１ This is a monovalent linear saturated hydrocarbon group having 1 to 10 carbon atoms, a monovalent aliphatic cyclic saturated hydrocarbon group having 3 to 20 carbon atoms, or a monovalent aromatic hydrocarbon group having 6 to 30 carbon atoms. Also, R Ｐ２ R is a single bond, a divalent chain saturated hydrocarbon group having 1 to 10 carbon atoms, a divalent aliphatic cyclic saturated hydrocarbon group having 3 to 20 carbon atoms, or a divalent aromatic hydrocarbon group having 6 to 30 carbon atoms. However, R Ｐ１ and R Ｐ２ Some or all of the hydrogen atoms in the chain-like saturated hydrocarbon group, aliphatic cyclic saturated hydrocarbon group, and aromatic hydrocarbon group may be substituted with fluorine atoms. The aliphatic cyclic hydrocarbon group may have one or more of the substituents individually, or it may have one or more of each of the substituents. Examples of monovalent chain-like saturated hydrocarbon groups having 1 to 10 carbon atoms include methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, and decyl groups. Examples of monovalent aliphatic cyclic saturated hydrocarbon groups having 3 to 20 carbon atoms include monocyclic aliphatic saturated hydrocarbon groups such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, cyclodecyl, and cyclododecyl groups; and polycyclic aliphatic saturated hydrocarbon groups such as bicyclo[2.2.2]octanyl, tricyclo[5.2.1.02,6]decanyl, tricyclo[3.3.1.13,7]decanyl, tetracyclo[6.2.1.13,6.02,7]dodecanyl, and adamantyl groups. Examples of monovalent aromatic hydrocarbon groups having 6 to 30 carbon atoms include groups obtained by removing one hydrogen atom from an aromatic hydrocarbon ring, such as benzene, biphenyl, fluorene, naphthalene, anthracene, and phenanthrene.

[0070] Ra' ３ But, Ra' １ , Ra' ２When the cyclic group is bonded to any of the above to form a ring, the cyclic group is preferably a 4- to 7-membered ring, and more preferably a 4- to 6-membered ring. Specific examples of the cyclic group include a tetrahydropyranyl group and a tetrahydrofuranyl group.

[0071] Tertiary alkyl ester type acid-dissociating groups: Among the polar groups mentioned above, an example of an acid-dissociating group that protects a carboxyl group is the acid-dissociating group represented by the following general formula (a1-r-2). Of the acid-dissociating groups represented by the following formula (a1-r-2), those composed of alkyl groups may hereafter be referred to as "tertiary alkyl ester type acid-dissociating groups" for convenience.

[0072] [In the formula, Ra' ４ ~Ra' ６ Each of these is a hydrocarbon group, Ra' ５ , Ra' ６ They may be joined to each other to form a ring.

[0073] Ra' ４ Examples of hydrocarbon groups include linear or branched alkyl groups, linear or cyclic alkenyl groups, or cyclic hydrocarbon groups. ４ In the above, linear or branched alkyl groups, cyclic hydrocarbon groups (monocyclic aliphatic hydrocarbon groups, polycyclic aliphatic hydrocarbon groups, aromatic hydrocarbon groups) are defined as Ra' ３ Similar examples include Ra' ４ The linear or cyclic alkenyl group in Ra' is preferably an alkenyl group having 2 to 10 carbon atoms. ５ , Ra' ６ The hydrocarbon group is the Ra' mentioned above. ３ Similar examples include the above.

[0074] Ra' ５ and Ra' ６ When these groups bond to each other to form a ring, the following groups are preferably represented by the general formula (a1-r2-1), the general formula (a1-r2-2), and the general formula (a1-r2-3). On the other hand, Ra' ４ ~Ra' ６When these are independent hydrocarbon groups that are not bonded to each other, the groups represented by the following general formula (a1-r2-4) are preferred.

[0075] [In formula (a1-r2-1), Ra' １０ This represents a linear or branched alkyl group having 1 to 12 carbon atoms, which may be partially substituted with halogen atoms or heteroatom-containing groups. １１ Ra' １０ This indicates a group that forms an aliphatic cyclic group together with the bonded carbon atom. In formula (a1-r2-2), Ya is a carbon atom. Xa is a group that forms a cyclic hydrocarbon group together with Ya. Some or all of the hydrogen atoms in this cyclic hydrocarbon group may be substituted. Ra １０１ ~Ra １０３ Each of these is independently a hydrogen atom, a monovalent linear saturated hydrocarbon group having 1 to 10 carbon atoms, or a monovalent aliphatic cyclic saturated hydrocarbon group having 3 to 20 carbon atoms. Some or all of the hydrogen atoms in these linear saturated hydrocarbon groups and aliphatic cyclic saturated hydrocarbon groups may be substituted. Ra １０１ ~Ra １０３ Two or more of these may be bonded to each other to form a cyclic structure. In formula (a1-r2-3), Yaa is a carbon atom. Xaa is a group that forms an aliphatic cyclic group together with Yaa. Ra １０４ is an aromatic hydrocarbon group which may have substituents. In formula (a1-r2-4), Ra' １２ and Ra' １３ Each of these is independently a monovalent, chain-like saturated hydrocarbon group having 1 to 10 carbon atoms. Some or all of the hydrogen atoms in this chain-like saturated hydrocarbon group may be substituted. Ra' １４ This is a hydrocarbon group that may have substituents. * indicates a bond (the same applies hereafter).

[0076] In the above formula (a1 - r2 - 1), Ra' １０ This is a linear or branched alkyl group having 1 to 12 carbon atoms, which may be partially substituted with halogen atoms or heteroatom-containing groups.

[0077] Ra' １０In this context, the linear alkyl group has 1 to 12 carbon atoms, preferably 1 to 10 carbon atoms, and particularly preferably 1 to 5 carbon atoms. １０ In this, the branched alkyl group is the Ra' ３ Similar examples include the above.

[0078] Ra' １０ In this context, the alkyl group may be partially substituted with a halogen atom or a heteroatom-containing group. For example, some of the hydrogen atoms constituting the alkyl group may be substituted with a halogen atom or a heteroatom-containing group. Also, some of the carbon atoms constituting the alkyl group (such as a methylene group) may be substituted with a heteroatom-containing group. Examples of heteroatoms here include oxygen atoms, sulfur atoms, and nitrogen atoms. Examples of heteroatom-containing groups include (-O-), -C(=O)-O-, -O-C(=O)-, -C(=O)-NH-, -NH-, -S-, and -S(=O). ２ -, -S (=O) ２ Examples include -O-, etc.

[0079] In formula (a1-r2-1), Ra' １１ (Ra' １０ The aliphatic cyclic group formed with the bonded carbon atom is Ra' in formula (a1-r-1). ３ The aliphatic hydrocarbon groups (alicyclic hydrocarbon groups) listed above, which are monocyclic or polycyclic groups, are preferred. Among these, monocyclic alicyclic hydrocarbon groups are preferred, and specifically, cyclopentyl groups and cyclohexyl groups are more preferred.

[0080] In formula (a1-r2-2), the cyclic hydrocarbon group formed by Xa together with Ya is Ra' in formula (a1-r-1). ３ Examples include a group obtained by further removing one or more hydrogen atoms from a cyclic monovalent hydrocarbon group (aliphatic hydrocarbon group) in the above. The cyclic hydrocarbon group formed by Xa together with Ya may have substituents. An example of such substituent is the above Ra' ３ Examples include substituents similar to those that may be present on the cyclic hydrocarbon group in formula (a1-r2-2). １０１ ~Ra１０３ Examples of monovalent chain-like saturated hydrocarbon groups having 1 to 10 carbon atoms include methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, and decyl groups. １０１ ~Ra １０３ Examples of monovalent aliphatic cyclic saturated hydrocarbon groups having 3 to 20 carbon atoms include monocyclic aliphatic saturated hydrocarbon groups such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, cyclodecyl, and cyclododecyl groups; bicyclo[2.2.2]octanyl, tricyclo[5.2.1.0 ２，６ ] Decanyl group, tricyclo[3.3.1.1 ３，７ ] Decanyl group, tetracyclo[6.2.1.1 ３，６ . 0 ２，７ Examples include polycyclic aliphatic saturated hydrocarbon groups such as dodecanyl groups and adamantyl groups. １０１ ~Ra １０３ Of these, from the viewpoint of ease of synthesis, hydrogen atoms and monovalent chain saturated hydrocarbon groups having 1 to 10 carbon atoms are preferred, and among these, hydrogen atoms, methyl groups, and ethyl groups are more preferred, with hydrogen atoms being particularly preferred.

[0081] The above Ra １０１ ~Ra １０３ Examples of substituents on a chain-like saturated hydrocarbon group or an aliphatic cyclic saturated hydrocarbon group represented by the above Ra ｘ５ Similar bases can be cited.

[0082] Ra １０１ ~Ra １０３ Groups containing a carbon-carbon double bond formed by the bonding of two or more carbon atoms to each other to form a cyclic structure include, for example, cyclopentenyl group, cyclohexenyl group, methylcyclopentenyl group, methylcyclohexenyl group, cyclopentylideneethenyl group, and cyclohexyllideneethenyl group. Among these, cyclopentenyl group, cyclohexenyl group, and cyclopentylideneethenyl group are preferred from the viewpoint of ease of synthesis.

[0083] In formula (a1-r2-3), the aliphatic cyclic group formed by Xaa together with Yaa is Ra' in formula (a1-r-1). ３ The groups listed as aliphatic hydrocarbon groups that are monocyclic or polycyclic are preferred. In formula (a1-r2-3), Ra １０４ Aromatic hydrocarbon groups in this context include groups obtained by removing one or more hydrogen atoms from an aromatic hydrocarbon ring having 5 to 30 carbon atoms. Among these, Ra １０４ The group is preferably an aromatic hydrocarbon ring having 6 to 15 carbon atoms from which one or more hydrogen atoms have been removed; more preferably a group from which one or more hydrogen atoms have been removed from benzene, naphthalene, anthracene, or phenanthrene; even more preferably a group from which one or more hydrogen atoms have been removed from benzene, naphthalene, or anthracene; particularly preferably a group from which one or more hydrogen atoms have been removed from benzene or naphthalene; and most preferably a group from which one or more hydrogen atoms have been removed from benzene.

[0084] Ra in equation (a1-r2-3) １０４ Examples of substituents that may be present include methyl groups, ethyl groups, propyl groups, hydroxyl groups, carboxyl groups, halogen atoms, alkoxy groups (such as methoxy groups, ethoxy groups, propoxy groups, butoxy groups, etc.), and alkyloxycarbonyl groups.

[0085] In formula (a1-r2-4), Ra' １２ and Ra' １３ Each of these is independently a monovalent, chain-like saturated hydrocarbon group having 1 to 10 carbon atoms. １２ and Ra' １３ In this, the monovalent chain-like saturated hydrocarbon group having 1 to 10 carbon atoms is the above Ra １０１ ~Ra １０３ Examples include monovalent chain-like saturated hydrocarbon groups having 1 to 10 carbon atoms. Some or all of the hydrogen atoms in this chain-like saturated hydrocarbon group may be substituted. Ra' １２ and Ra' １３ Among these, alkyl groups having 1 to 5 carbon atoms are preferred, alkyl groups having 1 to 5 carbon atoms are more preferred, methyl groups and ethyl groups are even more preferred, and methyl groups are particularly preferred. １２ and Ra'１３ When a chain-like saturated hydrocarbon group represented by is substituted, the substituent may be, for example, the above-mentioned Ra ｘ５ Similar bases can be cited.

[0086] In formula (a1-r2-4), Ra' １４ Ra' is a hydrocarbon group that may have substituents. １４ Examples of hydrocarbon groups in this context include linear or branched alkyl groups, or cyclic hydrocarbon groups.

[0087] Ra' １４ The linear alkyl group in this compound preferably has 1 to 5 carbon atoms, more preferably 1 to 4, and even more preferably 1 or 2. Specifically, examples include methyl group, ethyl group, n-propyl group, n-butyl group, n-pentyl group, etc. Among these, methyl group, ethyl group, or n-butyl group is preferred, and methyl group or ethyl group is more preferred.

[0088] Ra' １４ The branched alkyl group in the compound preferably has 3 to 10 carbon atoms, and more preferably 3 to 5. Specifically, examples include isopropyl group, isobutyl group, tert-butyl group, isopentyl group, neopentyl group, 1,1-diethylpropyl group, 2,2-dimethylbutyl group, etc., with isopropyl group being preferred.

[0089] Ra' １４ When the hydrocarbon group is cyclic, it may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group, and may be a polycyclic or monocyclic group. As a monocyclic aliphatic hydrocarbon group, a group obtained by removing one hydrogen atom from a monocycloalkane is preferred. The monocycloalkane is preferably one having 3 to 6 carbon atoms, specifically cyclopentane, cyclohexane, etc. As a polycyclic aliphatic hydrocarbon group, a group obtained by removing one hydrogen atom from a polycycloalkane is preferred, and the polycycloalkane is preferably one having 7 to 12 carbon atoms, specifically adamantane, norbornane, isobornane, tricyclo[5.2.1.0 ２，６ Examples include decane and tetracyclododecane.

[0090] Ra' １４ As for aromatic hydrocarbon groups in this context, Ra １０４ Examples include those similar to aromatic hydrocarbon groups in [the text]. Among them, Ra' １４ The group is preferably an aromatic hydrocarbon ring having 6 to 15 carbon atoms with one or more hydrogen atoms removed, more preferably a group from benzene, naphthalene, anthracene, or phenanthrene with one or more hydrogen atoms removed, even more preferably a group from benzene, naphthalene, or anthracene with one or more hydrogen atoms removed, particularly preferably a group from naphthalene or anthracene with one or more hydrogen atoms removed, and most preferably a group from naphthalene with one or more hydrogen atoms removed. １４ A substituent that may be present is Ra １０４ Examples of substituents that may be present include those similar to those that the molecule may have.

[0091] Ra' in equation (a1-r2-4) １４ When is a naphthyl group, the position of bonding to the tertiary carbon atom in formula (a1-r2-4) may be either position 1 or position 2 of the naphthyl group. １４ If is an anthyl group, the position of bonding to the tertiary carbon atom in formula (a1-r2-4) may be position 1, 2, or 9 of the anthyl group.

[0092] Specific examples of the group represented by the above formula (a1-r2-1) are given below.

[0093]

[0094]

[0095]

[0096] Specific examples of the group represented by the above formula (a1-r2-2) are given below.

[0097]

[0098]

[0099]

[0100] Specific examples of the group represented by the above formula (a1-r2-3) are given below.

[0101]

[0102] Specific examples of the group represented by the above formula (a1-r2-4) are given below.

[0103]

[0104] Tertiary alkyloxycarbonylic acid dissociable group: Among the polar groups, an example of an acid-dissociable group that protects a hydroxyl group is the acid-dissociable group represented by the following general formula (a1-r-3) (hereinafter referred to as a "tertiary alkyloxycarbonylic acid dissociable group" for convenience).

[0105] [In the formula, Ra' ７ ~Ra' ９ These are each alkyl groups.

[0106] In formula (a1-r-3), Ra' ７ ~Ra' ９ Each alkyl group is preferably an alkyl group having 1 to 5 carbon atoms, and more preferably an alkyl group having 1 to 3 carbon atoms. Furthermore, the total number of carbon atoms in each alkyl group is preferably 3 to 7, more preferably 3 to 5, and most preferably 3 to 4.

[0107] Secondary alkyl ester type acid-dissociating groups: Among the polar groups mentioned above, an example of an acid-dissociating group that protects a carboxyl group is the acid-dissociating group represented by the following general formula (a1-r-4).

[0108] [In the formula, Ra' １０ Ra' is a hydrocarbon group. １１ａ and Ra' １１ｂ Each of these is independently a hydrogen atom, a halogen atom, or an alkyl group. Ra' １２ Ra' is a hydrogen atom or a hydrocarbon group. １０ and Ra' １１ａ Or Ra' １１ｂ These may be joined together to form a ring. １１ａ Or Ra' １１ｂ And, Ra'１２ These elements may be joined together to form a ring.

[0109] In the formula, Ra' １０ and Ra' １２ The hydrocarbon group in this is the Ra' group. ３ Similar examples can be given. In the formula, Ra' １１ａ and Ra' １１ｂ The alkyl group in is the Ra' １ Examples include alkyl groups similar to those in the formula. In the formula, Ra' １０ and Ra' １２ The hydrocarbon group in, and Ra' １１ａ and Ra' １１ｂ The alkyl group in may have substituents. For example, the above-mentioned Ra ｘ５ These are some examples.

[0110] Ra' １０ and Ra' １１ａ Or Ra' １１ｂ These elements may bond to each other to form a ring. This ring may be polycyclic or monocyclic, and may be alicyclic or aromatic. The alicyclic and aromatic rings may contain heteroatoms.

[0111] Ra' １０ and Ra' １１ａ Or Ra' １１ｂ The rings formed by the bonding of these elements are preferably monocycloalkenes, rings in which some of the carbon atoms of a monocycloalkene are substituted with heteroatoms (oxygen atoms, sulfur atoms, etc.), monocycloalkadienes, cycloalkenes having 3 to 6 carbon atoms, and cyclopentene or cyclohexene.

[0112] Ra' １０ and Ra' １１ａ Or Ra' １１ｂ The ring formed by the bonding of these elements may be a fused ring. Specific examples of such fused rings include indane.

[0113] Ra' １０ and Ra' １１ａ Or Ra' １１ｂThe ring formed by the bonding of these elements may have substituents. For example, the above-mentioned Ra ｘ５ These are some examples.

[0114] Ra' １１ａ Or Ra' １１ｂ And, Ra' １２ These elements may be bonded together to form a ring, and the ring may be Ra' １０ and Ra' １１ａ Or Ra' １１ｂ Examples include rings formed by the bonding of these elements together.

[0115] Specific examples of the group represented by the above formula (a1-r-4) are given below.

[0116]

[0117] Examples of the constituent unit (a1) include a constituent unit derived from an acrylic acid ester in which the hydrogen atom bonded to the α-carbon atom may be substituted with a substituent, a constituent unit derived from acrylamide, a constituent unit derived from hydroxystyrene or a hydroxystyrene derivative in which at least a portion of the hydrogen atoms in the hydroxyl group of the constituent unit is protected by a substituent containing the acid-degradable group, and a constituent unit derived from vinylbenzoic acid or a vinylbenzoic acid derivative in which at least a portion of the hydrogen atoms in the -C(=O)-OH group is protected by a substituent containing the acid-degradable group.

[0118] As for the constituent unit (a1), among the above, a constituent unit derived from an acrylic acid ester in which the hydrogen atom bonded to the α-carbon atom may be substituted with a substituent is preferred. Preferred specific examples of such constituent unit (a1) include the constituent units represented by the following general formulas (a1-1), (a1-2), or (a1-3).

[0119] [In the formula, R is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or an alkyl halogen having 1 to 5 carbon atoms. Va １ n is a divalent hydrocarbon group which may have an ether bond. ａ１ is an integer between 0 and 2. １This is an acid-dissociable group represented by the general formula (a1-r-1), (a1-r-2), or (a1-r-4) above. Wa １ han ａ２ It is a +1 valent hydrocarbon group. ａ２ Ra is an integer between 1 and 3. ２ This is an acid-dissociable group represented by the general formula (a1-r-1) or (a1-r-3) above. ００１ It is a single bond or a divalent linking group. ０１ It is a single bond or a divalent linking group. Rax ０１ Rz is an acid-dissociable group represented by the general formula (a1-r-1), (a1-r-2), or (a1-r-4) above. ０１ [q is an alkyl group, a halogen atom, an alkyl halide, a hydroxyl group, or an alkoxy group. q is an integer between 0 and 3. n is an integer greater than or equal to 0, where n ≤ q × 2 + 4.]

[0120] In formulas (a1-1) to (a1-3), the C1-C5 alkyl group of R is preferably a linear or branched alkyl group having 1 to 5 carbon atoms, specifically including methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, tert-butyl, pentyl, isopentyl, and neopentyl groups. The C1-C5 halogenated alkyl group is a group in which some or all of the hydrogen atoms of the C1-C5 alkyl group are substituted with halogen atoms. Fluorine atoms are particularly preferred as the halogen atoms. R is preferably a hydrogen atom, a C1-C5 alkyl group, or a C1-C5 fluorinated alkyl group, with hydrogen atoms or methyl groups being the most preferred due to their industrial availability.

[0121] In the above formula (a1-1), Va １ The divalent hydrocarbon group in this expression may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group.

[0122] Va １The aliphatic hydrocarbon group as the divalent hydrocarbon group in this product may be saturated or unsaturated, but is usually preferred to be saturated. More specifically, examples of such aliphatic hydrocarbon group include linear or branched aliphatic hydrocarbon groups, or aliphatic hydrocarbon groups containing a ring in their structure.

[0123] The linear aliphatic hydrocarbon group preferably has 1 to 10 carbon atoms, more preferably 1 to 6 carbon atoms, even more preferably 1 to 4 carbon atoms, and most preferably 1 to 3 carbon atoms. A linear alkylene group is preferred as the linear aliphatic hydrocarbon group, specifically a methylene group [-CH] ２ -], ethylene group [- (CH ２ ) ２ -], trimethylene group [-(CH ２ ) ３ -], tetramethylene group [-(CH ２ ) ４ -], pentamethylene group [-(CH ２ ) ５ Examples include -]. The branched aliphatic hydrocarbon group preferably has 2 to 10 carbon atoms, more preferably 3 to 6 carbon atoms, even more preferably 3 or 4 carbon atoms, and most preferably 3 carbon atoms. A branched alkylene group is preferred as the branched aliphatic hydrocarbon group, specifically -CH(CH ３ )-,-CH(CH ２ CH ３ )-,-C(CH ３ ) ２ -, -C(CH ３ ) (CH ２ CH ３ )-,-C(CH ３ ) (CH ２ CH ２ CH ３ )-,-C(CH ２ CH ３ ) ２ - Alkyl methylene groups such as -CH(CH ３ )CH ２ -, -CH(CH ３ )CH(CH ３ )-,-C(CH ３ )２ CH ２ -, -CH(CH ２ CH ３ )CH ２ -, -C(CH ２ CH ３ ) ２ -CH ２ - Alkyl ethylene groups such as -CH(CH ３ )CH ２ CH ２ -ien-CH ２ CH (CH ３ )CH ２ - Alkyl trimethylene groups such as -CH(CH ３ )CH ２ CH ２ CH ２ -ien-CH ２ CH (CH ３ )CH ２ CH ２ Examples include alkylalkylene groups such as alkyltetramethylene groups. In the alkylalkylene group, a linear alkyl group having 1 to 5 carbon atoms is preferred.

[0124] Examples of aliphatic hydrocarbon groups containing a ring in the structure include alicyclic hydrocarbon groups (groups obtained by removing two hydrogen atoms from an aliphatic hydrocarbon ring), groups in which an alicyclic hydrocarbon group is bonded to the end of a linear or branched aliphatic hydrocarbon group, and groups in which an alicyclic hydrocarbon group is interposed in the middle of a linear or branched aliphatic hydrocarbon group. Examples of the linear or branched aliphatic hydrocarbon group include those similar to the linear or branched aliphatic hydrocarbon group. The alicyclic hydrocarbon group preferably has 3 to 20 carbon atoms, and more preferably 3 to 12 carbon atoms. The alicyclic hydrocarbon group may be polycyclic or monocyclic. As a monocyclic alicyclic hydrocarbon group, a group obtained by removing two hydrogen atoms from a monocycloalkane is preferred. The monocycloalkane preferably has 3 to 6 carbon atoms, and specifically examples include cyclopentane and cyclohexane. As for the polycyclic alicyclic hydrocarbon group, a group obtained by removing two hydrogen atoms from a polycycloalkane is preferred, and the polycycloalkane is preferably one having 7 to 12 carbon atoms, specifically adamantane, norbornane, isobornane, tricyclo[5.2.1.0 ２，６ Examples include decane and tetracyclododecane.

[0125] Va １In this context, the aromatic hydrocarbon group as a divalent hydrocarbon group is a hydrocarbon group having an aromatic ring. Such an aromatic hydrocarbon group preferably has 3 to 30 carbon atoms, more preferably 5 to 30, even more preferably 5 to 20, particularly preferably 6 to 15, and most preferably 6 to 12. However, this number of carbon atoms does not include the number of carbon atoms in substituents. Specific examples of aromatic rings in an aromatic hydrocarbon group include aromatic hydrocarbon rings such as benzene, biphenyl, fluorene, naphthalene, anthracene, and phenanthrene; and aromatic heterocycles in which some of the carbon atoms constituting the aromatic hydrocarbon ring are substituted with heteroatoms. Examples of heteroatoms in an aromatic heterocycle include oxygen atoms, sulfur atoms, and nitrogen atoms. Specifically, examples of the aromatic hydrocarbon group include a group obtained by removing two hydrogen atoms from the aromatic hydrocarbon ring (arylene group); and a group obtained by removing one hydrogen atom from the aromatic hydrocarbon ring (aryl group) in which one hydrogen atom is replaced by an alkylene group (for example, a group obtained by removing one more hydrogen atom from the aryl group in an arylalkyl group such as a benzyl group, phenethyl group, 1-naphthylmethyl group, 2-naphthylmethyl group, 1-naphthylethyl group, 2-naphthylethyl group, etc.). The number of carbon atoms in the alkylene group (alkyl chain in an arylalkyl group) is preferably 1 to 4, more preferably 1 to 2, and particularly preferably 1.

[0126] In the above formula (a1-1), Ra １ The acid-dissociable group is preferably represented by the general formula (a1-r-2) or (a1-r-4) described above, and among these, the group represented by the general formula (a1-r2-1) or the acid-dissociable group represented by the general formula (a1-r-4) is more preferred.

[0127] In the above formula (a1-2), Wa １ n in ａ２The +1 valent hydrocarbon group may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group. The aliphatic hydrocarbon group means a hydrocarbon group that does not have aromaticity, and may be saturated or unsaturated, but is usually preferred to be saturated. Examples of the aliphatic hydrocarbon group include a linear or branched aliphatic hydrocarbon group, an aliphatic hydrocarbon group containing a ring in its structure, or a group that is a combination of a linear or branched aliphatic hydrocarbon group and an aliphatic hydrocarbon group containing a ring in its structure. ａ２ The +1 valency is preferably 2 to 4 valencies, and more preferably 2 or 3 valencies. In the above formula (a1-2), Ra ２ The acid-dissociable group represented by the above general formula (a1-r-1) is preferred.

[0128] In the above formula (a1-3), Ya ００１ The divalent linking group in this is not particularly limited, but suitable examples include divalent hydrocarbon groups which may have substituents, and divalent linking groups which contain heteroatoms. ００１ Preferably, the alkylene group is an ester bond [-C(=O)-O-, -O-C(=O)-], an ether bond (-O-), a linear or branched alkylene group, an aromatic hydrocarbon group or a combination thereof, or a single bond. The number of carbon atoms in the alkylene group is preferably 1 to 10, more preferably 1 to 6, even more preferably 1 to 4, and particularly preferably 1 to 3. Among these, Ya ００１ The combination of an ester bond [-C(=O)-O-, -O-C(=O)-] and a linear alkylene group is more preferable, and a single bond is even more preferable.

[0129] In the above formula (a1-3), Ya ０１ The divalent linking group in this is not particularly limited, but suitable examples include a divalent hydrocarbon group which may have substituents, a divalent linking group which contains a heteroatom, and so on. ０１Among the above, it is preferable that the ester bond [-C(=O)-O-, -O-C(=O)-], ether bond (-O-), linear or branched alkylene group, aromatic hydrocarbon group or a combination thereof, or single bond. Among these, Ya ０１ The combination of an ester bond [-C(=O)-O-, -O-C(=O)-] and a linear alkylene group is more preferable, and a single bond is even more preferable.

[0130] In the above formula (a1-3), Rax ０１ The acid-dissociable group is preferably represented by the general formula (a1-r-2) or (a1-r-4) described above, and among these, the acid-dissociable group represented by the general formula (a1-r-2) is more preferred, and the group represented by the general formula (a1-r2-1) is even more preferred.

[0131] In the above formula (a1-3), Rz ０１ The alkyl group, alkyl halide, and alkoxy group in the above is preferably having 1 to 10 carbon atoms, more preferably 1 to 5 carbon atoms, even more preferably 1 to 3 carbon atoms, and particularly preferably 1 or 2 carbon atoms. The alkyl group, alkyl halide, and alkoxy group may be linear or branched. Rz ０１ In this case, iodine is preferred as the halogen atom. ０１ In the alkyl halide, the halogen atom is preferably a fluorine atom, an iodine atom, or a bromine atom, with a fluorine atom being more preferred. Rz ０１ The group is preferably an alkoxy group or a hydroxyl group, with a hydroxyl group being more preferred.

[0132] In formula (a1-3), q is an integer from 0 to 3. When q is 0, it is a benzene structure; when q is 1, it is a naphthalene structure; when q is 2, it is an anthracene structure; and when q is 3, it is a tetracene structure. In formula (a1-3), n is an integer of 0 or more, preferably from 0 to 5, more preferably from 0 to 3, and even more preferably 1 or 2. When n is an integer of 2 or more, Rz is 2 or more. ０１These can be the same or different. In the above formula (a1-3), n ≤ q × 2 + 4. For example, if q is 1 and the structure is naphthalene, then all six hydrogen atoms of the naphthalene are Rz ０１ It may be substituted with Ya ００１ , -Ya ０１ -C(=O)-O-Rax ０１ Base, and Rz ０１ The substitution position is not particularly limited.

[0133] The following are specific examples of constituent units (a1). In each of the following formulas, R α This represents a hydrogen atom, a methyl group, or a trifluoromethyl group.

[0134]

[0135]

[0136]

[0137]

[0138]

[0139]

[0140]

[0141]

[0142]

[0143] In the following equations, R α Rz represents a hydrogen atom, a methyl group, or a trifluoromethyl group. Rz represents a hydrogen atom, an alkyl group, a halogen atom, an alkyl halide, a hydroxyl group, or an alkoxy group.

[0144]

[0145]

[0146]

[0147]

[0148]

[0149] As for the constituent unit (a1), the constituent unit represented by formula (a1-1) or the constituent unit represented by formula (a1-3) is more preferable because it is easier to improve the characteristics (sensitivity, shape, etc.) in electron beam or EUV lithography. Acid-dissociable group (Ra １ Rax ０１ As for the components, it is preferable that they are acid-dissociable groups represented by the general formulas (a1-r2-1), (a1-r2-2), (a1-r2-4), or (a1-r-4), respectively, as these enhance reactivity for use in EB or EUV applications. Among these, from the viewpoint of increasing the glass transition temperature (Tg) of component (A1-0) and suppressing acid diffusion, the component represented by the formula (a1-3) is even more preferable as the component (a1); acid-dissociable group (Ra １ Rax ０１ The acid-dissociable group is more preferably an acid-dissociable group represented by the general formula (a1-r2-1), (a1-r2-4), or (a1-r-4), and even more preferably an acid-dissociable group represented by the general formula (a1-r2-1) or (a1-r2-4), and among these, it is particularly preferable to select one in which the acid-dissociable group is a cyclic group.

[0150] The constituent unit (a1) of component (A1-0) may be one type or two or more types. The proportion of constituent unit (a1) in component (A1-0) is preferably 5 to 80 mol%, more preferably 10 to 70 mol%, even more preferably 20 to 65 mol%, and particularly preferably 25 to 65 mol%, relative to the total (100 mol%) of all constituent units that make up component (A1-0). By setting the proportion of constituent unit (a1) to be above the lower limit of the above preferred range, lithography characteristics such as sensitivity, roughness, exposure margin, and resolution are improved. On the other hand, if it is below the upper limit of the above preferred range, a balance with other constituent units can be achieved, resulting in good lithography characteristics in various aspects.

[0151] <<Other Constituent Units>> Preferred (A1-0) components may have other constituent units in addition to the constituent unit (a1) described above, as needed. Examples of other constituent units include the constituent unit (a10) represented by the general formula (a10-1) described later; the constituent unit (a2) containing a lactone-containing cyclic group; the constituent unit (a5) that generates acid upon exposure; the constituent unit (a6) that has acid diffusion controllability; and the constituent unit (a8) derived from the compound represented by the general formula (a8-1) described later.

[0152] Regarding the constituent unit (a10) represented by the general formula (a10-1): The constituent unit (a10) is a constituent unit represented by the following general formula (a10-1).

[0153] [In the formula, R is an alkyl group having 1 to 5 carbon atoms, an alkyl halide having 1 to 5 carbon atoms, or a hydrogen atom. Ya ｘ１ Wa is a single bond or a divalent linking group. ｘ１ n is an aromatic hydrocarbon group which may have substituents. ａｘ１ [ is an integer greater than or equal to 1.]

[0154] In formula (a10-1), R is the same as R in general formula (a1-1). R is preferably a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a fluorinated alkyl group having 1 to 5 carbon atoms, and a hydrogen atom or a methyl group is particularly preferred due to their industrial availability.

[0155] In the above formula (a10-1), Ya ｘ１ is a single bond or a divalent linking group. In the above chemical formula, Ya ｘ１ The divalent linking group in this is not particularly limited, but suitable examples include divalent hydrocarbon groups which may have substituents, and divalent linking groups which contain heteroatoms.

[0156] - Divalent hydrocarbon groups which may have substituents: Divalent hydrocarbon groups which may have substituents may be aliphatic hydrocarbon groups or aromatic hydrocarbon groups.

[0157] ...Aliphatic hydrocarbon group An aliphatic hydrocarbon group means a hydrocarbon group that does not possess aromaticity. The aliphatic hydrocarbon group may be saturated or unsaturated, but is usually preferred to be saturated. Examples of the aliphatic hydrocarbon group include linear or branched aliphatic hydrocarbon groups, or aliphatic hydrocarbon groups that contain a ring in their structure.

[0158] ...Linear or branched aliphatic hydrocarbon group The linear aliphatic hydrocarbon group preferably has 1 to 10 carbon atoms, more preferably 1 to 6 carbon atoms, even more preferably 1 to 4 carbon atoms, and most preferably 1 to 3 carbon atoms. As the linear aliphatic hydrocarbon group, a linear alkylene group is preferred, specifically a methylene group [-CH ２ -], ethylene group [- (CH ２ ) ２ -], trimethylene group [-(CH ２ ) ３ -], tetramethylene group [-(CH ２ ) ４ -], pentamethylene group [-(CH ２ ) ５ Examples include -]. The branched aliphatic hydrocarbon group preferably has 2 to 10 carbon atoms, more preferably 3 to 6 carbon atoms, even more preferably 3 or 4 carbon atoms, and most preferably 3 carbon atoms. A branched alkylene group is preferred as the branched aliphatic hydrocarbon group, specifically -CH(CH ３ )-,-CH(CH ２ CH ３ )-,-C(CH ３ ) ２ -, -C(CH ３ ) (CH ２ CH ３ )-,-C(CH ３ ) (CH ２ CH ２ CH ３ )-,-C(CH ２ CH ３ ) ２ - Alkyl methylene groups such as -CH(CH ３ )CH ２ -, -CH(CH ３ )CH(CH ３)-,-C(CH ３ ) ２ CH ２ -, -CH(CH ２ CH ３ )CH ２ -, -C(CH ２ CH ３ ) ２ -CH ２ - Alkyl ethylene groups such as -CH(CH ３ )CH ２ CH ２ -ien-CH ２ CH (CH ３ )CH ２ - Alkyl trimethylene groups such as -CH(CH ３ )CH ２ CH ２ CH ２ -ien-CH ２ CH (CH ３ )CH ２ CH ２ Examples include alkylalkylene groups such as alkyltetramethylene groups. In the alkylalkylene group, a linear alkyl group having 1 to 5 carbon atoms is preferred.

[0159] The linear or branched aliphatic hydrocarbon group may or may not have substituents. Examples of substituents include fluorine atoms, fluorinated alkyl groups having 1 to 5 carbon atoms substituted with fluorine atoms, and carbonyl groups.

[0160] ...Aliphatic hydrocarbon groups containing a ring in their structure Examples of aliphatic hydrocarbon groups containing a ring in their structure include cyclic aliphatic hydrocarbon groups (groups obtained by removing two hydrogen atoms from an aliphatic hydrocarbon ring), which may contain substituents containing heteroatoms in their ring structure; groups in which the cyclic aliphatic hydrocarbon group is bonded to the end of a linear or branched aliphatic hydrocarbon group; and groups in which the cyclic aliphatic hydrocarbon group is interposed in the middle of a linear or branched aliphatic hydrocarbon group. Examples of the linear or branched aliphatic hydrocarbon group are the same as those described above. The cyclic aliphatic hydrocarbon group preferably has 3 to 20 carbon atoms, and more preferably has 3 to 12 carbon atoms. The cyclic aliphatic hydrocarbon group may be a polycyclic group or a monocyclic group. As a monocyclic alicyclic hydrocarbon group, a group obtained by removing two hydrogen atoms from a monocycloalkane is preferred. As a monocycloalkane, those having 3 to 6 carbon atoms are preferred, and specifically examples include cyclopentane and cyclohexane. As for the polycyclic alicyclic hydrocarbon group, a group obtained by removing two hydrogen atoms from a polycycloalkane is preferred, and as the polycycloalkane, those having 7 to 12 carbon atoms are preferred, specifically adamantane, norbornane, isobornane, tricyclo[5.2.1.0 ２，６ Examples include decane and tetracyclododecane.

[0161] The cyclic aliphatic hydrocarbon group may or may not have substituents. Examples of substituents include alkyl groups, alkoxy groups, halogen atoms, alkyl halides, hydroxyl groups, and carbonyl groups. Preferably, the alkyl group is a C1-C5 alkyl group, more preferably a methyl group, ethyl group, propyl group, n-butyl group, or tert-butyl group. Preferably, the alkoxy group is a C1-C5 alkoxy group, more preferably a methoxy group, ethoxy group, n-propoxy group, iso-propoxy group, n-butoxy group, or tert-butoxy group, and even more preferably a methoxy group or ethoxy group. Preferably, the halogen atom is a fluorine atom. Examples of alkyl halides are groups in which some or all of the hydrogen atoms of the alkyl group are substituted with halogen atoms. The cyclic aliphatic hydrocarbon group may also have some of the carbon atoms constituting its ring structure substituted with substituents containing heteroatoms. Substituents containing the heteroatom include -O-, -C(=O)-O-, -S-, and -S(=O). ２ -, -S (=O) ２ -O- is preferred.

[0162] ...Aromatic hydrocarbon group The aromatic hydrocarbon group is a hydrocarbon group having at least one aromatic ring. This aromatic ring is not particularly limited as long as it is a cyclic conjugated system having 4n+2 π electrons, and may be monocyclic or polycyclic. The number of carbon atoms in the aromatic ring is preferably 5 to 30, more preferably 5 to 20, even more preferably 6 to 15, and particularly preferably 6 to 12. However, this number of carbon atoms does not include the number of carbon atoms in substituents. Specific examples of aromatic rings include aromatic hydrocarbon rings such as benzene, naphthalene, anthracene, and phenanthrene; and aromatic heterocycles in which some of the carbon atoms constituting the aromatic hydrocarbon ring are substituted with heteroatoms. Examples of heteroatoms in aromatic heterocycles include oxygen atoms, sulfur atoms, and nitrogen atoms. Specific examples of aromatic heterocycles include pyridine rings and thiophene rings. Specific examples of aromatic hydrocarbon groups include: a group obtained by removing two hydrogen atoms from the aromatic hydrocarbon ring or aromatic heterocycle (arylene group or heteroarylene group); a group obtained by removing two hydrogen atoms from an aromatic compound containing two or more aromatic rings (e.g., biphenyl, fluorene, etc.); and a group obtained by removing one hydrogen atom from the aromatic hydrocarbon ring or aromatic heterocycle (aryl group or heteroaryl group) in which one hydrogen atom is replaced by an alkylene group (e.g., a group obtained by removing one more hydrogen atom from the aryl group in an arylalkyl group such as benzyl group, phenethyl group, 1-naphthylmethyl group, 2-naphthylmethyl group, 1-naphthylethyl group, 2-naphthylethyl group, etc.). The number of carbon atoms in the alkylene group bonded to the aryl group or heteroaryl group is preferably 1 to 4, more preferably 1 to 2, and particularly preferably 1.

[0163] The aromatic hydrocarbon group may have its hydrogen atoms substituted with substituents. For example, the hydrogen atoms bonded to the aromatic ring in the aromatic hydrocarbon group may be substituted with substituents. Examples of such substituents include alkyl groups, alkoxy groups, halogen atoms, alkyl halides, and hydroxyl groups. The alkyl group substituent is preferably an alkyl group having 1 to 5 carbon atoms, and more preferably a methyl group, ethyl group, propyl group, n-butyl group, or tert-butyl group. Examples of the alkoxy group, halogen atom, and alkyl halide substituent are those exemplified as substituents that substitute for hydrogen atoms in the cyclic aliphatic hydrocarbon group.

[0164] • Divalent linking groups containing heteroatoms: Examples of divalent linking groups containing heteroatoms include -O-, -C(=O)-O-, -O-C(=O)-, -C(=O)-, -O-C(=O)-O-, -C(=O)-NH-, -NH-, -NH-C(=NH)- (H may be substituted with substituents such as alkyl groups or acyl groups), -S-, -S(=O) ２ -, -S (=O) ２ -O-, general formula -Y ２１ -O-Y ２２ -, -Y ２１ -O-, -Y ２１ -C(=O)-O-, -C(=O)-O-Y ２１ -, -[Y ２１ -C (=O) -O] ｍ” -Y ２２ -, -Y ２１ -OC(=O)-Y ２２ - or - Y ２１ -S (=O) ２ -O-Y ２２ - is represented by the base [wherein Y ２１ and Y ２２Each of these is a divalent hydrocarbon group which may independently have substituents, O is an oxygen atom, and m'' is an integer from 1 to 3. For example, when the divalent linking group containing the heteroatom is -C(=O)-NH-, -C(=O)-NH-C(=O)-, -NH-, -NH-C(=NH)-, the H may be substituted with substituents such as alkyl groups or acyl groups. The substituent (alkyl group, acyl group, etc.) preferably has 1 to 10 carbon atoms, more preferably 1 to 8, and particularly preferably 1 to 5. General formula -Y ２１ -O-Y ２２ -, -Y ２１ -O-, -Y ２１ -C(=O)-O-, -C(=O)-O-Y ２１ -, -[Y ２１ -C (=O) -O] ｍ” -Y ２２ -, -Y ２１ -OC(=O)-Y ２２ - or - Y ２１ -S (=O) ２ -O-Y ２２ - Middle, Y ２１ and Y ２２ Each of these is independently a divalent hydrocarbon group which may have substituents. Examples of such divalent hydrocarbon groups are those described above. ２１ Preferably, a linear aliphatic hydrocarbon group is preferred, a linear alkylene group is more preferred, a linear alkylene group having 1 to 5 carbon atoms is even more preferred, and a methylene group or ethylene group is particularly preferred. ２２ Preferably, the group is a linear or branched aliphatic hydrocarbon group, more preferably a methylene group, an ethylene group, or an alkylmethylene group. The alkyl group in the alkylmethylene group is preferably a linear alkyl group having 1 to 5 carbon atoms, more preferably a linear alkyl group having 1 to 3 carbon atoms, and most preferably a methyl group. Formula - [Y ２１ -C (=O) -O] ｍ” -Y ２２ In the base represented by -, m'' is an integer from 1 to 3, preferably 1 or 2, and more preferably 1. That is, formula -[Y ２１ -C (=O) -O] ｍ”-Y ２２ As a base represented by -, see formula -Y ２１ -C(=O)-O-Y ２２ Groups represented by - are particularly preferred. Among them, the group represented by formula - (CH ２ ) ａ’ -C(=O)-O-(CH ２ ) ｂ’ A base represented by - is preferred. In the formula, a' is an integer from 1 to 10, preferably an integer from 1 to 8, more preferably an integer from 1 to 5, even more preferably 1 or 2, and most preferably 1. b' is an integer from 1 to 10, preferably an integer from 1 to 8, more preferably an integer from 1 to 5, even more preferably 1 or 2, and most preferably 1.

[0165] Ya ｘ１ Preferred members include single bonds, ester bonds [-C(=O)-O-, -O-C(=O)-], ether bonds (-O-), linear or branched alkylene groups, or combinations thereof, with single bonds and ester bonds [-C(=O)-O-, -O-C(=O)-] being more preferred.

[0166] In the above formula (a10-1), Wa ｘ１ Wa is an aromatic hydrocarbon group which may have substituents. ｘ１ The aromatic hydrocarbon group in this case is an aromatic ring which may have substituents (n ａｘ１ A group with 1+1 hydrogen atoms removed is an example. The aromatic ring here is not particularly limited as long as it is a cyclic conjugated system having 4n+2 π electrons. The number of carbon atoms in the aromatic ring is preferably 5 to 30, more preferably 5 to 20, even more preferably 6 to 15, and particularly preferably 6 to 12. Specific examples of the aromatic ring include aromatic hydrocarbon rings such as benzene, naphthalene, anthracene, and phenanthrene; and aromatic heterocycles in which some of the carbon atoms constituting the aromatic hydrocarbon ring are substituted with heteroatoms. Examples of heteroatoms in aromatic heterocycles include oxygen atoms, sulfur atoms, and nitrogen atoms. Specific examples of aromatic heterocycles include pyridine rings and thiophene rings. ｘ１The aromatic hydrocarbon group in this context is an aromatic compound containing an aromatic ring which may have two or more substituents (e.g., biphenyl, fluorene, etc.) (n ａｘ１ A group with 1) hydrogen atoms removed can also be cited. Among the above, Wa ｘ１ For example, (n ａｘ１ A group with (+1) hydrogen atoms removed is preferred, and (n ａｘ１ A group with (+1) hydrogen atoms removed is more preferable, and from benzene (n ａｘ１ A group with 1) hydrogen atoms removed is even more preferable.

[0167] Wa ｘ１ The aromatic hydrocarbon group in may or may not have substituents. Examples of substituents include alkyl groups, alkoxy groups, halogen atoms, and alkyl halides. Examples of alkyl groups, alkoxy groups, halogen atoms, and alkyl halides as substituents include Ya ｘ１ Examples of substituents for cyclic aliphatic hydrocarbon groups in the above are similar to those listed above. The substituents are preferably linear or branched alkyl groups having 1 to 5 carbon atoms, more preferably linear or branched alkyl groups having 1 to 3 carbon atoms, even more preferably ethyl or methyl groups, and particularly preferably methyl groups. Wa ｘ１ In this context, it is preferable that the aromatic hydrocarbon group does not have substituents.

[0168] In the above formula (a10-1), n ａｘ１ is an integer of 1 or more, preferably an integer from 1 to 10, more preferably an integer from 1 to 5, even more preferably 1, 2, or 3, and particularly preferably 1 or 2.

[0169] The following are specific examples of the constituent unit (a10) represented by the above formula (a10-1). In each of the following formulas, R α represents a hydrogen atom, a methyl group, or a trifluoromethyl group.

[0170]

[0171]

[0172]

[0173] The constituent unit (a10) of component (A1-0) may be one type or two or more types. Component (A1-0) may or may not have constituent unit (a10), but it is preferable that it has constituent unit (a10). When component (A1-0) has constituent unit (a10), the proportion of constituent unit (a10) in component (A1-0) is preferably 20 to 80 mol%, more preferably 20 to 70 mol%, even more preferably 25 to 65 mol%, and particularly preferably 25 to 60 mol%, relative to the total (100 mol%) of all constituent units that make up component (A1-0). By setting the proportion of constituent unit (a10) to be above the lower limit of the above preferred range, sensitivity can be more easily increased. On the other hand, by setting it to be below the upper limit of the above preferred range, it becomes easier to balance it with other constituent units.

[0174] Regarding the constituent unit (a2) containing a lactone-containing cyclic group: Component (A1-0) may or may not have a constituent unit (a2) containing a lactone-containing cyclic group (excluding those corresponding to constituent unit (a1)). The lactone-containing cyclic group of constituent unit (a2) is effective in improving the adhesion of the resist film to the substrate when component (A1-0) is used to form a resist film. Furthermore, having constituent unit (a2) improves lithography characteristics, etc., by having effects such as appropriately adjusting the acid diffusion length, improving the adhesion of the resist film to the substrate, and appropriately adjusting the solubility during development.

[0175] A "lactone-containing cyclic group" refers to a cyclic group that contains a ring (lactone ring) containing -O-C(=O)- within its cyclic skeleton. The lactone ring is counted as the first ring. If it consists only of a lactone ring, it is called a monocyclic group; if it also has other ring structures, it is called a polycyclic group regardless of those structures. A lactone-containing cyclic group may be a monocyclic group or a polycyclic group. Any lactone-containing cyclic group can be used in the constituent unit (a2) without any particular limitations. Specifically, examples include the groups represented by the following general formulas (a2-r-1) to (a2-r-7).

[0176] [In the formula, Ra' ２１ Each of these is independently a hydrogen atom, an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, -COOR'', -OC(=O)R'', a hydroxyalkyl group, or a cyano group; R'' is a hydrogen atom, an alkyl group, or a lactone-containing cyclic group; A'' is an alkylene group having 1 to 5 carbon atoms, which may contain an oxygen atom (-O-) or a sulfur atom (-S-), an oxygen atom, or a sulfur atom, where n' is an integer from 0 to 2, and m' is 0 or 1. * indicates a bond (the same applies below).

[0177] In the general formulas (a2-r-1) to (a2-r-7), Ra' ２１ The alkyl group in is preferably an alkyl group having 1 to 6 carbon atoms. The alkyl group is preferably linear or branched. Specifically, examples include methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, isobutyl group, tert-butyl group, pentyl group, isopentyl group, neopentyl group, hexyl group, etc. Among these, the methyl group or ethyl group is preferred, and the methyl group is particularly preferred. Ra' ２１ The alkoxy group in is preferably an alkoxy group having 1 to 6 carbon atoms. The alkoxy group is preferably linear or branched. Specifically, the Ra' ２１ Examples of alkyl groups in this context include groups formed by linking an alkyl group with an oxygen atom (-O-). ２１ In this, a fluorine atom is preferred as the halogen atom. Ra' ２１ The halogenated alkyl group in is the Ra' ２１ Examples include groups in which some or all of the hydrogen atoms of the alkyl group are substituted with the halogen atoms. Fluorinated alkyl groups are preferred as the halogenated alkyl groups, and perfluoroalkyl groups are particularly preferred.

[0178] Ra' ２１In -COOR'' and -OC(=O)R'', R'' is a hydrogen atom, an alkyl group, or a lactone-containing cyclic group. The alkyl group in R'' may be linear, branched, or cyclic, and preferably has 1 to 15 carbon atoms. If R'' is a linear or branched alkyl group, it preferably has 1 to 10 carbon atoms, more preferably 1 to 5 carbon atoms, and is particularly preferably a methyl group or an ethyl group. If R'' is a cyclic alkyl group, it preferably has 3 to 15 carbon atoms, more preferably 4 to 12 carbon atoms, and most preferably 5 to 10 carbon atoms. Specifically, examples include a group obtained by removing one or more hydrogen atoms from a monocycloalkane, which may or may not be substituted with a fluorine atom or a fluorinated alkyl group; and a group obtained by removing one or more hydrogen atoms from a polycycloalkane such as bicycloalkanes, tricycloalkanes, or tetracycloalkanes. More specifically, groups obtained by removing one or more hydrogen atoms from monocycloalkanes such as cyclopentane and cyclohexane; adamantane, norbornane, isobornane, tricyclo[5.2.1.0 ２，６ Examples include groups obtained by removing one or more hydrogen atoms from polycycloalkanes such as decane and tetracyclododecane. Examples of lactone-containing cyclic groups in R'' include those similar to the groups represented by the general formulas (a²-r-1) to (a²-r-7) above. Ra' ２１ The hydroxyalkyl group in is preferably one having 1 to 6 carbon atoms, specifically the Ra' ２１ Examples include groups in which at least one hydrogen atom of the alkyl group is substituted with a hydroxyl group.

[0179] Ra' ２１ Among the above, it is preferable that each is independently a hydrogen atom or a cyano group.

[0180] In the general formulas (a2-r-2), (a2-r-3), and (a2-r-5), the alkylene group having 1 to 5 carbon atoms in A'' is preferably a linear or branched alkylene group, such as a methylene group, ethylene group, n-propylene group, isopropylene group, etc. When the alkylene group contains an oxygen atom or a sulfur atom, a specific example is a group in which -O- or -S- is interposed at the end or between carbon atoms of the alkylene group, for example, -O-CH ２ -ien-CH ２ -O-CH ２ -, -S-CH ２ -ien-CH ２ -S-CH ２ Examples include the following. A'' is preferably an alkylene group or -O- having 1 to 5 carbon atoms, more preferably an alkylene group having 1 to 5 carbon atoms, and most preferably a methylene group.

[0181] The following are specific examples of the groups represented by the general formulas (a²-r-1) to (a²-r-7).

[0182]

[0183]

[0184] Among the constituent units (a2), those derived from acrylic acid esters in which the hydrogen atom bonded to the α-carbon atom may be substituted with a substituent are preferred. Such constituent units (a2) are preferably those represented by the following general formula (a2-1).

[0185] [In the formula, R is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or an alkyl halogen having 1 to 5 carbon atoms. Ya ２１ It is a single bond or a divalent linking group. La ２１ The elements are -O-, -COO-, -CON(R')-, -OCO-, -CONHCO-, or -CONHCS-, where R' represents a hydrogen atom or a methyl group. However, La ２１ If -O-, Ya ２１ It does not become -CO-. Ra ２１ This is a lactone-containing cyclic group.

[0186] In formula (a2-1) above, R is the same as above. R is preferably a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a fluorinated alkyl group having 1 to 5 carbon atoms, and a hydrogen atom or a methyl group is particularly preferred due to their industrial availability.

[0187] In the above formula (a2-1), Ya ２１ The divalent linking group in this is not particularly limited, but suitable examples include divalent hydrocarbon groups which may have substituents, and divalent linking groups which contain heteroatoms. ２１ The divalent linking group in the above general formula (a10-1) is Ya ｘ１ Examples include divalent linking groups similar to those in [the relevant context].

[0188] Ya ２１ Preferably, the group is a single bond, an ester bond [-C(=O)-O-], an ether bond (-O-), a linear or branched alkylene group, or a combination thereof.

[0189] In the above formula (a2-1), Ya ２１ It is a single bond, La ２１ It is preferable that it be -COO- or -OCO-.

[0190] In the formula (a2-1), Ra ２１ Ra is a lactone-containing cyclic group. ２１ Suitable lactone-containing cyclic groups in this compound include the groups represented by the general formulas (a2-r-1) to (a2-r-7) mentioned above.

[0191] The constituent unit (a2) of component (A1-0) may be one type or two or more types. Component (A1-0) may or may not contain constituent unit (a2). When component (A1-0) contains constituent unit (a2), the proportion of constituent unit (a2) is preferably 1 to 20 mol%, more preferably 1 to 15 mol%, and even more preferably 1 to 10 mol%, relative to the total (100 mol%) of all constituent units that make up component (A1-0). By setting the proportion of constituent unit (a2) to be above the lower limit of the above preferred range, the effects of including constituent unit (a2) can be fully obtained through the effects described above. On the other hand, by setting it to be below the upper limit of the above preferred range, a balance can be achieved with other constituent units, resulting in good lithography characteristics in various fields.

[0192] Regarding the constituent unit (a5) that generates acid upon exposure: Component (A1-0) may or may not have a constituent unit (a5) that generates acid upon exposure. Known constituent units (a5) can be used. Having a constituent unit (a5) makes it easier for the acid generated upon exposure to be uniformly distributed within the resist film. Having a constituent unit (a5) makes it easier for the acid generated upon exposure to be uniformly distributed within the resist film. Examples of constituent units (a5) include a constituent unit containing the structure described in component (B) below. For example, an example of a constituent unit (a5) is the constituent unit represented by the following general formula (a5-1).

[0193] [In the formula, R ｍ This is an alkyl group having 1 to 5 carbon atoms, an alkyl halide having 1 to 5 carbon atoms, a halogen atom, or a hydrogen atom. La ５０ This is a divalent linking group or a single bond. Ra ５０ n is a divalent hydrocarbon group which may have substituents. ａ５ It is an integer between 0 and 2. ５１ It is a divalent linking group. ５ This is a divalent linking group that may have a heteroatom, or a single bond. Ra５１ and Ra ５２ Each of these is independently a hydrogen atom, a fluorine atom, or a fluorinated alkyl group. n5 is an integer from 1 to 4. m is an integer of 1 or more, and M' ｍ＋ This is an onium cation with a valence of m.

[0194] {Anion part} In the above formula (a5-1), R ｍ R is an alkyl group having 1 to 5 carbon atoms, an alkyl halide having 1 to 5 carbon atoms, a halogen atom, or a hydrogen atom. ｍ The alkyl group having 1 to 5 carbon atoms is preferably a linear or branched alkyl group having 1 to 5 carbon atoms, specifically including methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, tert-butyl, pentyl, isopentyl, and neopentyl groups. The halogenated alkyl group having 1 to 5 carbon atoms is a group in which some or all of the hydrogen atoms of the alkyl group having 1 to 5 carbon atoms are substituted with halogen atoms. Examples of halogen atoms include fluorine, chlorine, bromine, and iodine atoms. Fluorine is particularly preferred as the halogen atom in the halogenated alkyl group. ｍ Preferably, the group consists of a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a fluorinated alkyl group having 1 to 5 carbon atoms, with the hydrogen atom or methyl group being the most preferred due to their industrial availability.

[0195] In the formula (a5-1), La ５０ This is a divalent linking group or a single bond. La ５０ The divalent linking group in is not particularly limited, but preferred examples include a divalent hydrocarbon group which may have substituents, and a divalent linking group which contains a heteroatom, respectively. ｘ１ The divalent linking groups in the above are similar to the divalent hydrocarbon groups that may have substituents and divalent linking groups containing heteroatoms, as exemplified. ５０Preferably, the bonds are ester bonds [-C(=O)-O-, -O-C(=O)-], ether bonds (-O-), linear or branched alkylene groups, aromatic hydrocarbon groups or combinations thereof, or single bonds. Among these, La ５ As such, ester bonds [-C(=O)-O-, -O-C(=O)-] and single bonds are more preferable, and ester bonds [-C(=O)-O-, -O-C(=O)-] are even more preferable.

[0196] In the formula (a5-1), Ra ５０ This is a divalent hydrocarbon group which may have substituents. Ra ５０ The divalent hydrocarbon group in this expression may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group.

[0197] ...Ra ５０ In this context, the aliphatic hydrocarbon group refers to a hydrocarbon group that does not possess aromaticity. The aliphatic hydrocarbon group may be saturated or unsaturated, but is usually preferred to be saturated. Examples of the aliphatic hydrocarbon group include linear or branched aliphatic hydrocarbon groups, or aliphatic hydrocarbon groups containing a ring in their structure.

[0198] ...Linear or branched aliphatic hydrocarbon group The linear aliphatic hydrocarbon group preferably has 1 to 10 carbon atoms, more preferably 1 to 6 carbon atoms, even more preferably 1 to 4 carbon atoms, and most preferably 1 to 3 carbon atoms. As the linear aliphatic hydrocarbon group, a linear alkylene group is preferred, specifically a methylene group [-CH ２ -], ethylene group [- (CH ２ ) ２ -], trimethylene group [-(CH ２ ) ３ -], tetramethylene group [-(CH ２ ) ４ -], pentamethylene group [-(CH ２ ) ５Examples include -]. The branched aliphatic hydrocarbon group preferably has 2 to 10 carbon atoms, more preferably 3 to 6 carbon atoms, even more preferably 3 or 4 carbon atoms, and most preferably 3 carbon atoms. A branched alkylene group is preferred as the branched aliphatic hydrocarbon group, specifically -CH(CH ３ )-,-CH(CH ２ CH ３ )-,-C(CH ３ ) ２ -, -C(CH ３ ) (CH ２ CH ３ )-,-C(CH ３ ) (CH ２ CH ２ CH ３ )-,-C(CH ２ CH ３ ) ２ - Alkyl methylene groups such as -CH(CH ３ )CH ２ -, -CH(CH ３ )CH(CH ３ )-,-C(CH ３ ) ２ CH ２ -, -CH(CH ２ CH ３ )CH ２ -, -C(CH ２ CH ３ ) ２ -CH ２ - Alkyl ethylene groups such as -CH(CH ３ )CH ２ CH ２ -ien-CH ２ CH (CH ３ )CH ２ - Alkyl trimethylene groups such as -CH(CH ３ )CH ２ CH ２ CH ２ -ien-CH ２ CH (CH ３ )CH ２ CH ２Examples include alkylalkylene groups such as alkyltetramethylene groups. In the alkylalkylene group, a linear alkyl group having 1 to 5 carbon atoms is preferred.

[0199] The linear or branched aliphatic hydrocarbon group described above may or may not have substituents. Examples of substituents include fluorine atoms, fluorinated alkyl groups having 1 to 5 carbon atoms substituted with fluorine atoms, and carbonyl groups.

[0200] ...Aliphatic hydrocarbon groups containing a ring in their structure Examples of aliphatic hydrocarbon groups containing a ring in their structure include cyclic aliphatic hydrocarbon groups (groups with two hydrogen atoms removed from an aliphatic hydrocarbon ring) which may contain substituents containing heteroatoms in their ring structure, groups in which the cyclic aliphatic hydrocarbon group is bonded to the end of a linear or branched aliphatic hydrocarbon group, and groups in which the cyclic aliphatic hydrocarbon group is interposed in the middle of a linear or branched aliphatic hydrocarbon group. Examples of the linear or branched aliphatic hydrocarbon group are the same as those described above. The cyclic aliphatic hydrocarbon group preferably has 3 to 20 carbon atoms, and more preferably has 3 to 12 carbon atoms. The cyclic aliphatic hydrocarbon group may be a polycyclic group or a monocyclic group. As a monocyclic alicyclic hydrocarbon group, a group in which two hydrogen atoms have been removed from a monocycloalkane is preferred. As a monocycloalkane, those having 3 to 6 carbon atoms are preferred, and specifically examples include cyclopentane and cyclohexane. As for the polycyclic alicyclic hydrocarbon group, a group obtained by removing two hydrogen atoms from a polycycloalkane is preferred, and as the polycycloalkane, those having 7 to 12 carbon atoms are preferred, specifically adamantane, norbornane, isobornane, tricyclo[5.2.1.0 ２，６ Examples include decane and tetracyclododecane.

[0201] The cyclic aliphatic hydrocarbon group may or may not have substituents. Examples of substituents include alkyl groups, alkoxy groups, halogen atoms, alkyl halides, hydroxyl groups, and carbonyl groups. Preferably, the alkyl group has 1 to 5 carbon atoms, and most preferably it is a methyl group, ethyl group, propyl group, n-butyl group, or tert-butyl group. Preferably, the alkoxy group has 1 to 5 carbon atoms, and more preferably it is a methoxy group, ethoxy group, n-propoxy group, iso-propoxy group, n-butoxy group, or tert-butoxy group, with methoxy and ethoxy groups being the most preferred. Examples of halogen atoms as substituents include fluorine atoms, chlorine atoms, bromine atoms, and iodine atoms, with fluorine atoms being preferred. Examples of alkyl halides as substituents include groups in which some or all of the hydrogen atoms of the alkyl group are substituted with halogen atoms. The cyclic aliphatic hydrocarbon group may have some of the carbon atoms constituting its ring structure substituted with substituents containing heteroatoms. Substituents containing the heteroatom include -O-, -C(=O)-O-, -S-, and -S(=O). ２ -, -S (=O) ２ -O- is preferred.

[0202] ...Ra ５０The aromatic hydrocarbon group in this context is a hydrocarbon group having at least one aromatic ring. This aromatic ring is not particularly limited as long as it is a cyclic conjugated system having 4n+2 π electrons, and may be monocyclic or polycyclic. The number of carbon atoms in the aromatic ring is preferably 5 to 30, more preferably 5 to 20, even more preferably 6 to 15, and particularly preferably 6 to 12. However, this number of carbon atoms does not include the number of carbon atoms in substituents. Specific examples of aromatic rings include aromatic hydrocarbon rings such as benzene, naphthalene, anthracene, and phenanthrene; and aromatic heterocycles in which some of the carbon atoms constituting the aromatic hydrocarbon ring are substituted with heteroatoms. Examples of heteroatoms in aromatic heterocycles include oxygen atoms, sulfur atoms, and nitrogen atoms. Specific examples of aromatic heterocycles include pyridine rings and thiophene rings. Specific examples of aromatic hydrocarbon groups include: a group obtained by removing two hydrogen atoms from the aromatic hydrocarbon ring or aromatic heterocycle (arylene group or heteroarylene group); a group obtained by removing two hydrogen atoms from an aromatic compound containing two or more aromatic rings (e.g., biphenyl, fluorene, etc.); and a group obtained by removing one hydrogen atom from the aromatic hydrocarbon ring or aromatic heterocycle (aryl group or heteroaryl group) in which one hydrogen atom is replaced by an alkylene group (e.g., a group obtained by removing one more hydrogen atom from the aryl group in an arylalkyl group such as benzyl group, phenethyl group, 1-naphthylmethyl group, 2-naphthylmethyl group, 1-naphthylethyl group, 2-naphthylethyl group, etc.). The number of carbon atoms in the alkylene group bonded to the aryl group or heteroaryl group is preferably 1 to 4, more preferably 1 to 2, and particularly preferably 1.

[0203] The aromatic hydrocarbon group may have its hydrogen atoms substituted with substituents. For example, the hydrogen atoms bonded to the aromatic ring in the aromatic hydrocarbon group may be substituted with substituents. Examples of substituents include alkyl groups, alkoxy groups, halogen atoms, alkyl halides, and hydroxyl groups. The alkyl group substituent is preferably an alkyl group having 1 to 5 carbon atoms, and most preferably a methyl group, ethyl group, propyl group, n-butyl group, or tert-butyl group. Examples of alkoxy groups, halogen atoms, and alkyl halides as substituents include those exemplified as substituents that substitute for hydrogen atoms in the cyclic aliphatic hydrocarbon group.

[0204] In the above formula (a5-1), n ａ５ is an integer between 0 and 2. Among the above, Ra ５０ Preferably, the aliphatic hydrocarbon group is an aliphatic hydrocarbon group containing a ring in its structure, more preferably a cyclic aliphatic hydrocarbon group which may contain substituents containing heteroatoms in its ring structure, and even more preferably a polycyclic or monocyclic alicyclic hydrocarbon group which may have substituents. Alternatively, among the above, Ra ５０ Aromatic hydrocarbon groups are preferred.

[0205] n ａ５ If it is 2, then two Ra ５０ These may all be alicyclic hydrocarbon groups which may have substituents, or they may all be aromatic hydrocarbon groups which may have substituents, or they may be a combination of alicyclic hydrocarbon groups which may have substituents and aromatic hydrocarbon groups which may have substituents.

[0206] In the formula (a5-1), La ５１ It is a divalent linking group. La ５１Examples of divalent linking groups in this context include non-hydrocarbon oxygen atom-containing linking groups such as oxygen atoms (ether bond: -O-), ester bonds (-C(=O)-O-), oxycarbonyl groups (-O-C(=O)-), amide bonds (-C(=O)-NH-), carbonyl groups (-C(=O)-), and carbonate bonds (-O-C(=O)-O-); and combinations of these non-hydrocarbon oxygen atom-containing linking groups with alkylene groups. In addition to these combinations, sulfonyl groups (-SO) may be added. ２ A ∫(-) may be linked. Examples of such divalent linking groups include the linking groups represented by the following general formulas (L-al-1) to (L-al-8). Note that in the following general formulas (L-al-1) to (L-al-8), Ra in formula (a5-1) above ５０ The combination with this is V' in the following general formulas (L-al-1) to (L-al-8). １０１ That is the case.

[0207] [In the formula, V' １０１ V' is a single bond or an alkylene group having 1 to 5 carbon atoms. １０２ [This refers to a divalent saturated hydrocarbon group having 1 to 30 carbon atoms.]

[0208] V' １０２ The divalent saturated hydrocarbon group in is preferably an alkylene group having 1 to 30 carbon atoms, more preferably an alkylene group having 1 to 10 carbon atoms, and even more preferably an alkylene group having 1 to 5 carbon atoms.

[0209] V' １０１ and V' １０２ The alkylene group in V' may be a linear alkylene group or a branched alkylene group, but a linear alkylene group is preferred. １０１ and V' １０２ Specifically, the alkylene group in this case is the methylene group [-CH ２ -come; -CH(CH ３ )-,-CH(CH ２ CH ３ )-,-C(CH ３ ) ２ -, -C(CH ３ ) (CH ２CH ３ )-,-C(CH ３ ) (CH ２ CH ２ CH ３ )-,-C(CH ２ CH ３ ) ２ - Alkylmethylene groups such as; ethylene groups [-CH ２ CH ２ -come; -CH(CH ３ )CH ２ -, -CH(CH ３ )CH(CH ３ )-,-C(CH ３ ) ２ CH ２ -, -CH(CH ２ CH ３ )CH ２ - Alkylethylene groups such as; trimethylene group (n-propylene group) [-CH ２ CH ２ CH ２ -come; -CH(CH ３ )CH ２ CH ２ -ien-CH ２ CH (CH ３ )CH ２ - Alkyl trimethylene groups such as; tetramethylene groups [-CH ２ CH ２ CH ２ CH ２ -come; -CH(CH ３ )CH ２ CH ２ CH ２ -ien-CH ２ CH (CH ３ )CH ２ CH ２ - Alkyltetramethylene groups such as; pentamethylene groups [-CH ２ CH ２ CH ２ CH ２ CH ２ -] are some examples. Also, V' １０１ or V' １０２ Some of the methylene groups in the alkylene group may be substituted with a divalent aliphatic cyclic group having 5 to 10 carbon atoms. The aliphatic cyclic group is Ra' in formula (a1-r-1).３ A divalent group is preferred, which is obtained by removing one more hydrogen atom from a cyclic aliphatic hydrocarbon group (a monocyclic aliphatic hydrocarbon group or a polycyclic aliphatic hydrocarbon group), and a cyclohexylene group, a 1,5-adamantilene group, or a 2,6-adamantilene group is more preferred.

[0210] La ５１ Preferably, the linking group is a divalent linking group containing an ester bond or a divalent linking group containing an ether bond, more preferably the linking groups represented by the above formulas (L-al-1) to (L-al-5) and (L-al-8), and even more preferably the linking group represented by the above formula (L-al-3) or (L-al-8).

[0211] In the above formula (a5-1), Ya ５ This is a divalent linking group that may have a heteroatom, or a single bond. ５ The divalent linking group in this is not particularly limited, but suitable examples include divalent hydrocarbon groups which may have substituents, and divalent linking groups which contain heteroatoms. ５ In the above, the divalent hydrocarbon group which may have substituents, and the divalent linking group which contains a heteroatom, are as follows: ｘ１ This is similar to the divalent linking groups exemplified in the above, such as divalent hydrocarbon groups which may have substituents, and divalent linking groups which contain heteroatoms. Among the above, Ya ５ The alkylene group is preferably a linear or branched alkylene group, or a single bond, with a single bond being more preferable.

[0212] In the formula (a5-1), Ra ５１ and Ra ５２ Each of these is independently a hydrogen atom, a fluorine atom, or a fluorinated alkyl group. Ra ５１ and Ra ５２ The fluorinated alkyl group in is preferably a linear or branched fluorinated alkyl group having 1 to 5 carbon atoms, and more preferably a trifluoromethyl group. In formula (a5-1), SO ３ － Ra bonded to the adjacent carbon atom ５１ and Ra ５２From the viewpoint of acid strength, it is preferable that at least one of these atoms is a fluorine atom.

[0213] In the above formula (a5-1), n5 is an integer from 1 to 4, and is preferably 1, 2, or 3.

[0214] {Cation part} In the above formula (a5-1), M' ｍ＋ This represents an m-valent onium cation. Among these, M' ｍ＋ m is preferably a sulfonium cation or an iodonium cation.

[0215] Preferred cation portion ((M' ｍ＋ ) １／ｍ Examples of onium cations include those represented by the following general formulas (ca-1) to (ca-3).

[0216] [In the formula, R ２０１ ~R ２０７ Each of these independently represents an optionally substituted aryl group, an optionally substituted alkyl group, or an optionally substituted alkenyl group. ２０１ ~R ２０３ , R ２０６ ~R ２０７ These atoms may bond to each other to form a ring with the sulfur atom in the formula. ２０８ ~R ２０９ Each of these independently represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms. ２１０ This may be an aryl group having a substituent, an alkyl group having a substituent, an alkenyl group having a substituent, or an -SO group having a substituent. ２ - Contains a cyclic group. L ２０１ This represents -C(=O)- or -C(=O)-O-.

[0217] In the above general formulas (ca-1) to (ca-3), R ２０１ ~R ２０７ Examples of aryl groups in this compound include unsubstituted aryl groups having 6 to 20 carbon atoms, with phenyl and naphthyl groups being preferred. ２０１ ~R ２０７The alkyl group in is preferably a linear or cyclic alkyl group having 1 to 30 carbon atoms. ２０１ ~R ２０７ The alkenyl group in is preferably one with 2 to 10 carbon atoms. ２０１ ~R ２０７ , and R ２１０ Examples of substituents that may be present include alkyl groups, halogen atoms, alkyl halides, carbonyl groups, cyano groups, amino groups, aryl groups, and groups represented by the following general formulas (ca-r-1) to (ca-r-7).

[0218] [In the formula, R' ２０１ Each of these is independently a hydrogen atom, an optionally substituted cyclic group, an optionally substituted linear alkyl group, or an optionally substituted linear alkenyl group.

[0219] A cyclic group which may have substituents: The cyclic group is preferably a cyclic hydrocarbon group, which may be an aromatic hydrocarbon group or an aliphatic hydrocarbon group. An aliphatic hydrocarbon group means a hydrocarbon group that does not have aromaticity. Furthermore, the aliphatic hydrocarbon group may be saturated or unsaturated, but is usually preferred to be saturated.

[0220] R' ２０１ The aromatic hydrocarbon group in R' is a hydrocarbon group having an aromatic ring. The aromatic hydrocarbon group preferably has 3 to 30 carbon atoms, more preferably 5 to 30, even more preferably 5 to 20, particularly preferably 6 to 15, and most preferably 6 to 10. However, this carbon number does not include the carbon atoms in substituents. ２０１ Specific examples of aromatic rings in aromatic hydrocarbon groups include benzene, fluorene, naphthalene, anthracene, phenanthrene, biphenyl, or aromatic heterocycles in which some of the carbon atoms constituting these aromatic rings are substituted with heteroatoms. Examples of heteroatoms in aromatic heterocycles include oxygen atoms, sulfur atoms, nitrogen atoms, etc. ２０１Specific examples of aromatic hydrocarbon groups in this context include groups obtained by removing one hydrogen atom from the aromatic ring (aryl groups: e.g., phenyl group, naphthyl group, etc.), and groups in which one of the hydrogen atoms of the aromatic ring is replaced by an alkylene group (e.g., arylalkyl groups such as benzyl group, phenethyl group, 1-naphthylmethyl group, 2-naphthylmethyl group, 1-naphthylethyl group, 2-naphthylethyl group, etc.). The number of carbon atoms in the alkylene group (alkyl chain in the arylalkyl group) is preferably 1 to 4, more preferably 1 to 2, and particularly preferably 1.

[0221] R' ２０１ The cyclic aliphatic hydrocarbon group in this context refers to an aliphatic hydrocarbon group that contains a ring in its structure. Examples of aliphatic hydrocarbon groups containing a ring in their structure include alicyclic hydrocarbon groups (groups from which one hydrogen atom has been removed from an aliphatic hydrocarbon ring), groups in which an alicyclic hydrocarbon group is bonded to the end of a linear or branched aliphatic hydrocarbon group, and groups in which an alicyclic hydrocarbon group is interposed in the middle of a linear or branched aliphatic hydrocarbon group. The alicyclic hydrocarbon group preferably has 3 to 20 carbon atoms, and more preferably 3 to 12 carbon atoms. The alicyclic hydrocarbon group may be a polycyclic group or a monocyclic group. A preferred monocyclic alicyclic hydrocarbon group is a group from which one or more hydrogen atoms have been removed from a monocycloalkane. The preferred monocycloalkane has 3 to 6 carbon atoms, and specifically includes cyclopentane and cyclohexane. A preferred polycyclic alicyclic hydrocarbon group is a group from which one or more hydrogen atoms have been removed from a polycycloalkane, and the preferred polycycloalkane has 7 to 30 carbon atoms. Among these, the polycycloalkanes include adamantane, norbornane, isobornane, and tricyclo[5.2.1.0 ２，６ Polycycloalkanes having a cross-linked ring system polycyclic skeleton, such as decane and tetracyclododecane; polycycloalkanes having a fused ring system polycyclic skeleton, such as a cyclic group having a steroid skeleton, are more preferred.

[0222] Among them, R' ２０１The cyclic aliphatic hydrocarbon group in is preferably a monocycloalkane or polycycloalkane from which one or more hydrogen atoms have been removed, more preferably a polycycloalkane from which one hydrogen atom has been removed, with adamantyl and norbornyl groups being particularly preferred, and the adamantyl group being the most preferred.

[0223] The linear or branched aliphatic hydrocarbon group, which may be bonded to the alicyclic hydrocarbon group, preferably has 1 to 10 carbon atoms, more preferably 1 to 6 carbon atoms, even more preferably 1 to 4 carbon atoms, and particularly preferably 1 to 3 carbon atoms. A linear alkylene group is preferred as the linear aliphatic hydrocarbon group, specifically a methylene group [-CH₂]. ２ -], ethylene group [- (CH ２ ) ２ -], trimethylene group [-(CH ２ ) ３ -], tetramethylene group [-(CH ２ ) ４ -], pentamethylene group [-(CH ２ ) ５ Examples include -CH(CH ３ )-,-CH(CH ２ CH ３ )-,-C(CH ３ ) ２ -, -C(CH ３ ) (CH ２ CH ３ )-,-C(CH ３ ) (CH ２ CH ２ CH ３ )-,-C(CH ２ CH ３ ) ２ - Alkyl methylene groups such as -CH(CH ３ )CH ２ -, -CH(CH ３ )CH(CH ３ )-,-C(CH ３ ) ２ CH ２ -, -CH(CH ２ CH ３ )CH ２-, -C(CH ２ CH ３ ) ２ -CH ２ - Alkyl ethylene groups such as -CH(CH ３ )CH ２ CH ２ -ien-CH ２ CH (CH ３ )CH ２ - Alkyl trimethylene groups such as -CH(CH ３ )CH ２ CH ２ CH ２ -ien-CH ２ CH (CH ３ )CH ２ CH ２ Examples include alkylalkylene groups such as alkyltetramethylene groups. In the alkylalkylene group, a linear alkyl group having 1 to 5 carbon atoms is preferred.

[0224] Also, R' ２０１ The cyclic hydrocarbon group in may contain heteroatoms, such as heterocycles. Specifically, lactone-containing cyclic groups represented by the general formulas (a2-r-1) to (a2-r-7) described above, and -SO groups represented by the general formulas (b5-r-1) to (b5-r-4) described later. ２ - Examples include cyclic groups and heterocyclic groups represented by the following chemical formulas (r-hr-1) to (r-hr-16).

[0225]

[0226] R' ２０１Examples of substituents on the cyclic group include alkyl groups, alkoxy groups, halogen atoms, alkyl halides, hydroxyl groups, carbonyl groups, and nitro groups. Preferred alkyl groups as substituents are alkyl groups having 1 to 5 carbon atoms, with methyl, ethyl, propyl, n-butyl, and tert-butyl groups being the most preferred. Preferred alkoxy groups as substituents are alkoxy groups having 1 to 5 carbon atoms, with methoxy, ethoxy, n-propoxy, iso-propoxy, n-butoxy, and tert-butoxy groups being more preferred, with methoxy and ethoxy groups being the most preferred. Preferred halogen atoms as substituents are fluorine atoms. Examples of alkyl halides as substituents include alkyl groups having 1 to 5 carbon atoms, such as methyl, ethyl, propyl, n-butyl, and tert-butyl groups, in which some or all of the hydrogen atoms are substituted with the halogen atoms. Carbonyl groups as substituents are methylene groups (-CH) that constitute the cyclic hydrocarbon group. ２ It is a substituting group for -).

[0227] A chain-like alkyl group which may have substituents: R' ２０１ The linear alkyl group may be linear or branched. Linear alkyl groups preferably have 1 to 20 carbon atoms, more preferably 1 to 15 carbon atoms, and most preferably 1 to 10 carbon atoms. Branched alkyl groups preferably have 3 to 20 carbon atoms, more preferably 3 to 15 carbon atoms, and most preferably 3 to 10 carbon atoms. Specifically, examples include 1-methylethyl group, 1-methylpropyl group, 2-methylpropyl group, 1-methylbutyl group, 2-methylbutyl group, 3-methylbutyl group, 1-ethylbutyl group, 2-ethylbutyl group, 1-methylpentyl group, 2-methylpentyl group, 3-methylpentyl group, and 4-methylpentyl group.

[0228] A chain-like alkenyl group which may have substituents: R' ２０１The linear alkenyl group may be linear or branched, preferably having 2 to 10 carbon atoms, more preferably 2 to 5 carbon atoms, even more preferably 2 to 4 carbon atoms, and particularly preferably 3 carbon atoms. Examples of linear alkenyl groups include vinyl groups, propenyl groups (allyl groups), and butenyl groups. Examples of branched alkenyl groups include 1-methylvinyl groups, 2-methylvinyl groups, 1-methylpropenyl groups, and 2-methylpropenyl groups. Among the linear alkenyl groups listed above, linear alkenyl groups are preferred, vinyl groups and propenyl groups are more preferred, and vinyl groups are particularly preferred.

[0229] R' ２０１ Examples of substituents in the chain-like alkyl or alkenyl group include alkoxy groups, halogen atoms, alkyl halides, hydroxyl groups, carbonyl groups, nitro groups, amino groups, and the above R'. ２０１ Examples include cyclic groups in this context.

[0230] R' ２０１ In addition to those mentioned above, the optionally substituted cyclic groups, optionally substituted linear alkyl groups, or optionally substituted linear alkenyl groups may also include those similar to the acid-dissociable group represented by formula (a1-r-2) above, as optionally substituted cyclic groups or optionally substituted linear alkyl groups.

[0231] Among them, R' ２０１ The cyclic group is preferably a cyclic group which may have substituents, and more preferably a cyclic hydrocarbon group which may have substituents. More specifically, for example, a phenyl group, a naphthyl group, a group obtained by removing one or more hydrogen atoms from a polycycloalkane; a lactone-containing cyclic group represented by the general formulas (a2-r-1) to (a2-r-7) described above; and -SO2 groups represented by the general formulas (b5-r-1) to (b5-r-4) described below. ２ - A cyclic group is preferred.

[0232] In the above general formulas (ca-1) to (ca-3), R ２０１ ~R ２０３ , R ２０６ ~R ２０７When these atoms bond to each other and form a ring with the sulfur atom in the formula, they can be heteroatoms such as sulfur, oxygen, and nitrogen atoms, or carbonyl groups, -SO-, -SO ２ -, -SO ３ -, -COO-, -CONH- or -N(R Ｎ )-(the R Ｎ is an alkyl group having 1 to 5 carbon atoms. ) may be bonded via functional groups such as ). The formed ring is preferably a 3 to 10-membered ring, and particularly preferably a 5 to 7-membered ring, including the sulfur atom in its ring skeleton. Specific examples of the formed ring include, for example, a thiophene ring, a thiazole ring, a benzothiophene ring, a dibenzothiophene ring, a 9H-thioxanthene ring, a thioxanthone ring, a thianthlene ring, a phenoxatiyne ring, a tetrahydrothiophenium ring, a tetrahydrothiopyranium ring, and the like.

[0233] R ２０８ ~R ２０９ Each of these independently represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, preferably a hydrogen atom or an alkyl group having 1 to 3 carbon atoms. If an alkyl group is formed, it may bond to each other to form a ring.

[0234] R ２１０ This may be an aryl group having a substituent, an alkyl group having a substituent, an alkenyl group having a substituent, or an -SO group having a substituent. ２ - Contains a cyclic group. R ２１０ Examples of aryl groups in this compound include unsubstituted aryl groups having 6 to 20 carbon atoms, with phenyl and naphthyl groups being preferred. ２１０ The alkyl group in is preferably a linear or cyclic alkyl group having 1 to 30 carbon atoms. ２１０ The alkenyl group in is preferably one with 2 to 10 carbon atoms. ２１０ In, -SO ２ - Any cyclic group can be used without any particular limitations. Specifically, the groups represented by the following general formulas (b5-r-1) to (b5-r-4) can be used, such as "-SO ２A polycyclic group containing a polycyclic group is preferred, and a group represented by the general formula (b5-r-1) is more preferred.

[0235] [In the formula, Rb' ５１ Each of these is independently a hydrogen atom, an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, -COOR'', -OC(=O)R'', a hydroxyalkyl group, or a cyano group; R'' is a hydrogen atom, an alkyl group, a lactone-containing cyclic group, or -SO ２ - It is a cyclic group containing; B'' is an alkylene group having 1 to 5 carbon atoms, which may contain an oxygen atom or a sulfur atom, an oxygen atom or a sulfur atom, and n' is an integer from 0 to 2. * indicates a bond.

[0236] In the general formulas (b5-r-1) to (b5-r-2) above, B'' is an alkylene group having 1 to 5 carbon atoms, which may contain an oxygen atom or a sulfur atom, an oxygen atom, or a sulfur atom. B'' is preferably an alkylene group having 1 to 5 carbon atoms or -O-, more preferably an alkylene group having 1 to 5 carbon atoms, and even more preferably a methylene group.

[0237] In the above general formulas (b5-r-1) to (b5-r-4), Rb' ５１ Each of these is independently a hydrogen atom, an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, -COOR'', -OC(=O)R'', a hydroxyalkyl group, or a cyano group, and among these, each is preferably independently a hydrogen atom or a cyano group.

[0238] Below are specific examples of the groups represented by the general formulas (b5-r-1) to (b5-r-4). In the formulas, "Ac" indicates an acetyl group.

[0239]

[0240]

[0241]

[0242] Specific examples of suitable cations represented by the above formula (ca-1) include the cations represented by the following chemical formulas.

[0243]

[0244]

[0245] [In the formula, g1, g2, and g3 represent the number of repetitions, where g1 is an integer from 1 to 5, g2 is an integer from 0 to 20, and g3 is an integer from 1 to 20.]

[0246]

[0247]

[0248] [In the formula, R” ２０１ is a hydrogen atom or a substituent, and the substituent is the aforementioned R ２０１ ~R ２０７ and R ２１０ These are the same as those listed as substituents that may be present.

[0249]

[0250] Specific examples of suitable cations represented by the formula (ca-2) include diphenyliodonium cation and bis(4-tert-butylphenyl)iodonium cation.

[0251] Specific examples of suitable cations represented by the above formula (ca-3) include the cations represented by the following formulas (ca-3-1) to (ca-3-6).

[0252]

[0253] The cation portion in the above formula (a5-1) ((M' ｍ＋ ) １／ｍAs the cation, a sulfonium cation is preferred, the cations represented by formulas (ca-1) to (ca-3) are more preferred, the cation represented by formula (ca-1) is even more preferred, and the cations represented by formulas (ca-1-1) to (ca-1-84) are particularly preferred. Particularly from the viewpoint of increasing sensitivity, the preferred cation represented by formula (ca-1) is one having electron-withdrawing groups such as a fluorine atom, a fluorinated alkyl group, or a sulfonyl group as a substituent, and for example, a cation selected from the group consisting of the cations represented by the above chemical formulas (ca-1-44), (ca-1-71) to (ca-1-84) is particularly preferred.

[0254] The following are preferred examples of the constituent unit (a5). In the following formula, R α m and M' represent a hydrogen atom, a methyl group, or a trifluoromethyl group. ｍ＋ These are m and M' in the above general formula (a5-1). ｍ＋ It is similar to that.

[0255]

[0256]

[0257]

[0258]

[0259] The constituent unit (a5) of component (A1-0) may be one type or two or more types. When component (A1-0) has constituent unit (a5), the proportion of constituent unit (a5) in component (A1-0) is preferably 5 to 25 mol%, more preferably 5 to 20 mol%, and even more preferably 10 to 20 mol%, relative to the total (100 mol%) of all constituent units that make up component (A1-0). If the proportion of constituent unit (a5) is above the lower limit of the above preferred range, it becomes easier to achieve further increases in sensitivity and improvements in resolution. On the other hand, if it is below the upper limit of the above preferred range, it becomes easier to balance with other constituent units.

[0260] Regarding the constituent unit (a6) having acid diffusion controllability: Constituent unit (a6) is a constituent unit having acid diffusion controllability. Component (A1-0) may or may not have constituent unit (a6). Constituent unit (a6) can be one of known types. Examples of constituent unit (a6) include constituent units containing the structures described in components (D1) and (D2) below. For example, a constituent unit containing a structure represented by any of the general formulas (d1-1) to (d1-3) below can be used.

[0261] The following are preferred examples of the constituent unit (a6). In the following formula, R α m and M' represent a hydrogen atom, a methyl group, or a trifluoromethyl group. ｍ＋ These are m and M' in the above general formula (a5-1). ｍ＋ It is similar to that.

[0262]

[0263] The constituent unit (a6) of component (A1-0) may be one type or two or more types. When component (A1-0) has constituent unit (a6), the proportion of constituent unit (a6) in component (A1-0) is preferably 1 to 20 mol%, more preferably 2 to 15 mol%, and even more preferably 3 to 10 mol%, relative to the total (100 mol%) of all constituent units that make up component (A1-0). If the proportion of constituent unit (a6) is above the lower limit of the above preferred range, it becomes easier to achieve even higher sensitivity. On the other hand, if it is below the upper limit of the above preferred range, it becomes easier to balance with other constituent units.

[0264] Regarding the constituent unit (a8) derived from the compound represented by the general formula (a8-1): The constituent unit (a8) is a constituent unit derived from the compound represented by the general formula (a8-1) below. Component (A1-0) may or may not have the constituent unit (a8).

[0265] [In the formula, W ２ This is a polymerizable group-containing group. ｘ２ is a single bond or (n ａｘ２ It is a linking group with a +1 valence. ｘ２ and W２ It may form a fused ring. １ R is a fluorinated alkyl group having 1 to 12 carbon atoms. ２ R is an organic group having 1 to 12 carbon atoms, which may contain a fluorine atom, or a hydrogen atom. ２ and Ya ｘ２ These may be bonded to each other to form a ring structure. ａｘ２ [This is an integer between 1 and 3.]

[0266] W ２ In the context of polymerizable group-containing groups, "polymerizable group" refers to a group that enables a compound containing a polymerizable group to polymerize by radical polymerization or the like, and includes, for example, a group containing multiple bonds between carbon atoms, such as an ethylenic double bond.

[0267] The polymerizable group-containing group may be a group composed solely of a polymerizable group, or a group composed of a polymerizable group and other groups other than the polymerizable group. Examples of other groups other than the polymerizable group include divalent hydrocarbon groups which may have substituents, and divalent linking groups containing heteroatoms. An example of a polymerizable group-containing group is a group with the chemical formula: C(R Ｘ１１ ) (Caution Ｘ１２ ) = C(R Ｘ１３ )-Ya ｘ０ The group represented by - is preferably mentioned. In this chemical formula, R Ｘ１１ , R Ｘ１２ and R Ｘ１３ These are, respectively, a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms, and Ya ｘ０ It is a single bond or a divalent linking group.

[0268] Ya ｘ２ and W ２ The condensed ring formed by these is W ２ Polymerizable groups of the site and Ya ｘ２ The condensed ring formed by and W ２ Other groups besides the polymerizable group of the site and Ya ｘ２ A condensed ring formed by these is an example. ｘ２ and W ２ The fused ring formed by these two components may have substituents.

[0269] The following shows specific examples of constituent units (a8). In the following formula, R α This represents a hydrogen atom, a methyl group, or a trifluoromethyl group.

[0270]

[0271] Among the above examples, the constituent unit (a8) is preferably at least one selected from the group consisting of constituent units represented by the chemical formulas (a8-1-01) to (a8-1-04), (a8-1-06), (a8-1-08), (a8-1-09), and (a8-1-10), and more preferably at least one selected from the group consisting of constituent units represented by the chemical formulas (a8-1-01) to (a8-1-04) and (a8-1-09).

[0272] The constituent unit (a8) of component (A1-0) may be one type or two or more types. Component (A1-0) may or may not have the constituent unit (a8). The proportion of constituent unit (a8) in component (A1-0) is preferably 0 to 50 mol%, and more preferably 0 to 30 mol%, relative to the total amount (100 mol%) of all constituent units that make up component (A1-0).

[0273] The (A1-0) component contained in the resist composition may be used alone or in combination of two or more types. In the resist composition of this embodiment, the (A1-0) component is a polymer in which a linking group represented by the general formula (a0-L) constitutes a part of the polymer main chain. Preferably, such (A1-0) component is a polymer compound in which a first copolymer is bonded to the bond side *1 and a second copolymer is bonded to the bond side *2 via the linking group. Preferably, the first copolymer and the second copolymer each contain a copolymer having a repeating structure of constituent unit (a1) and constituent unit (a10).

[0274] The first copolymer and the second copolymer can be, for example, a copolymer having a repeating structure of constituent unit (a1) and constituent unit (a10), or a copolymer having a repeating structure of constituent unit (a1), constituent unit (a10), and constituent unit (a5). Among these, the first copolymer and the second copolymer can be preferably copolymers having a repeating structure of constituent unit (a1), constituent unit (a10), and constituent unit (a5), as this makes it easier to further enhance the sensitivity and roughness reduction effect in resist pattern formation.

[0275] Specific examples of preferred (A1-0) components include polymer compounds in which copolymers consisting of repeating structures of constituent units (a1) and (a10) are linked together via a linking group represented by the general formula (a0-L); polymer compounds in which copolymers consisting of repeating structures of constituent units (a1), (a10), and (a5) are linked together via a linking group represented by the general formula (a0-L); and polymer compounds in which copolymers consisting of repeating structures of constituent units (a1), (a10), (a5), and (a6) are linked together via a linking group represented by the general formula (a0-L).

[0276] With respect to component (A1-0), in a copolymer consisting of a repeating structure of constituent units (a1) and constituent units (a10), the proportion of constituent units (a1) in the copolymer is preferably 25 to 75 mol%, more preferably 30 to 70 mol%, and even more preferably 40 to 60 mol%, based on the total amount (100 mol%) of all constituent units constituting the copolymer. The proportion of constituent units (a10) in the copolymer is preferably 25 to 75 mol%, more preferably 30 to 70 mol%, and even more preferably 40 to 60 mol%, based on the total amount (100 mol%) of all constituent units constituting the copolymer.

[0277] With respect to component (A1-0), in a copolymer consisting of a repeating structure of constituent units (a1), (a10), and (a5), the proportion of constituent unit (a1) in the copolymer is preferably 25 to 75 mol%, more preferably 30 to 70 mol%, and even more preferably 40 to 65 mol%, based on the total amount (100 mol%) of all constituent units constituting the copolymer. The proportion of constituent unit (a10) in the copolymer is preferably 20 to 45 mol%, more preferably 25 to 45 mol%, and even more preferably 25 to 40 mol%, based on the total amount (100 mol%) of all constituent units constituting the copolymer. The proportion of constituent unit (a5) in the copolymer is preferably 5 to 30 mol%, more preferably 5 to 25 mol%, and even more preferably 10 to 20 mol%, based on the total amount (100 mol%) of all constituent units constituting the copolymer.

[0278] With respect to component (A1-0), in a copolymer consisting of a repeating structure of constituent units (a1), (a10), (a5), and (a6), the proportion of constituent unit (a1) in the copolymer is preferably 25 to 75 mol%, more preferably 30 to 70 mol%, and even more preferably 40 to 62 mol%, based on the total amount (100 mol%) of all constituent units constituting the copolymer. The proportion of constituent unit (a10) in the copolymer is preferably 20 to 40 mol%, more preferably 23 to 35 mol%, and even more preferably 25 to 35 mol%, based on the total amount (100 mol%) of all constituent units constituting the copolymer. The proportion of constituent unit (a5) in the copolymer is preferably 4 to 25 mol%, more preferably 5 to 20 mol%, and even more preferably 10 to 20 mol%, based on the total amount (100 mol%) of all constituent units constituting the copolymer. The proportion of constituent units (a6) in the copolymer is preferably 1 to 15 mol%, more preferably 2 to 10 mol%, and even more preferably 3 to 5 mol%, relative to the total amount (100 mol%) of all constituent units that make up the copolymer.

[0279] The weight-average molecular weight (Mw) of component (A1-0) (based on polystyrene equivalent by gel permeation chromatography (GPC)) is not particularly limited, but is preferably 2000 to 30000, more preferably 3000 to 20000, and even more preferably 4000 to 12000. If the Mw of component (A1-0) is below the upper limit of the preferred range described above, the sensitivity in resist pattern formation is more easily improved, and it has sufficient solubility in resist solvents for use as a resist. On the other hand, if it is above the lower limit of the preferred range described above, it has good dry etching resistance and a good cross-sectional shape of the resist pattern. The dispersion degree (Mw / Mn) of component (A1-0) is not particularly limited, but is preferably 1.0 to 4.0, more preferably 1.0 to 3.0, and particularly preferably 1.0 to 2.0. Mn represents the number-average molecular weight.

[0280] ...Regarding component (A1-1) Component (A1-1) is a polymer whose solubility in the developer changes due to the action of an acid (excluding those corresponding to component (A1-0)). Component (A1-1) and component (A1-0) differ in at least whether or not a linking group represented by the general formula (a0-L) constitutes part of the polymer main chain. Preferably, this component (A1-1) has a constituent unit (a1) containing an acid-degradable group whose polarity increases due to the action of an acid, as described above. Preferred components (A1-1) may have other constituent units in addition to constituent unit (a1) as needed. Examples of other constituent units include the constituent units (a10), (a2), (a5), (a6), and (a8) described above. The resist composition may contain one type of component (A1-1) alone, or two or more types may be used in combination.

[0281] In the resist composition of this embodiment, component (A1) may consist only of component (A1-0), or it may be a combination of component (A1-0) and component (A1-1). The proportion of component (A1) in component (A1) is preferably 25% by mass or more, more preferably 50% by mass or more, even more preferably 75% by mass or more, and may be 100% by mass, based on the total mass of component (A1). When the proportion is 25% by mass or more, the effects of sensitivity and roughness reduction are both easily enhanced, and the effect of suppressing film thinning in the unexposed areas of the resist film is also easily improved.

[0282] Regarding component (A2), the resist composition of this embodiment may also use a base component (hereinafter referred to as "component (A2)") as component (A), which does not fall under component (A1) and whose solubility in the developer changes due to the action of an acid. Component (A2) is not particularly limited and may be arbitrarily selected from a large number of base components conventionally known for chemically amplified resist compositions.

[0283] In the resist composition of this embodiment, the content of component (A) may be adjusted according to the resist film thickness to be formed.

[0284] <Other Components> In addition to component (A) described above, the resist composition of this embodiment may further contain other components. Examples of other components include components (B), (D), (E), (F), and (S) shown below.

[0285] ≪Acid Generating Agent Component (B)≫ The resist composition of this embodiment may further contain an acid generating agent component (B) that generates acid upon exposure. Component (B) is not particularly limited, and any acid generating agent previously proposed for chemically amplified resist compositions can be used. Examples of such acid generating agents include onium salt-based acid generating agents such as iodonium salts and sulfonium salts, oxime sulfonate-based acid generating agents; diazomethane-based acid generating agents such as bisalkyl or bisarylsulfonyl diazomethanes and poly(bissulfonyl) diazomethanes; nitrobenzyl sulfonate-based acid generating agents, iminosulfonate-based acid generating agents, disulfone-based acid generating agents, and many others. Component (B) may be in the form of a compound, incorporated into component (A1) as the above-mentioned constituent unit (a5), or in both forms.

[0286] Examples of onium salt-based acid generators include the compound represented by the following general formula (b-1) (hereinafter also referred to as "component (b-1)"), the compound represented by the general formula (b-2) (hereinafter also referred to as "component (b-2)"), or the compound represented by the general formula (b-3) (hereinafter also referred to as "component (b-3)").

[0287] [In the formula, R １０１ and R １０４ ~R １０８ Each of these is independently a cyclic group which may have substituents, a linear alkyl group which may have substituents, or a linear alkenyl group which may have substituents. １０４ and R １０５ These may be bonded to each other to form a ring structure. １０２ This is a fluorinated alkyl group having 1 to 5 carbon atoms or a fluorine atom. １０１ This is a divalent linking group or single bond containing an oxygen atom. １０１ ~V １０３ Each of these is independently a single bond, an alkylene group, or a fluorinated alkylene group. However, Y １０１ and V １０１ They can never form a single bond. １０１ ~L １０２Each of these is independently either a single bond or an oxygen atom. １０３ ~L １０５ These are, independently, single bonds, -CO-, or -SO-. ２ - is true. m is an integer greater than or equal to 1, and M' ｍ＋ This is an onium cation with a positive (m) charge.

[0288] {Anion part} • In the anion formula (b-1) of component (b-1), R １０１ This is a cyclic group which may have substituents, a linear alkyl group which may have substituents, or a linear alkenyl group which may have substituents.

[0289] A cyclic group which may have substituents: The cyclic group is preferably a cyclic hydrocarbon group, which may be an aromatic hydrocarbon group or an aliphatic hydrocarbon group. An aliphatic hydrocarbon group means a hydrocarbon group that does not have aromaticity. Furthermore, the aliphatic hydrocarbon group is preferably saturated.

[0290] R １０１ The aromatic hydrocarbon group in is a hydrocarbon group having an aromatic ring. The number of carbon atoms in the aromatic hydrocarbon group is preferably 3 to 30, more preferably 5 to 30, even more preferably 5 to 20, particularly preferably 6 to 15, and most preferably 6 to 10. However, this number of carbon atoms does not include the number of carbon atoms in substituents. １０１ Specific examples of aromatic rings in aromatic hydrocarbon groups include benzene, fluorene, naphthalene, anthracene, phenanthrene, biphenyl, or aromatic heterocycles in which some of the carbon atoms constituting these aromatic rings are substituted with heteroatoms. Examples of heteroatoms in aromatic heterocycles include oxygen atoms, sulfur atoms, nitrogen atoms, etc. １０１Specific examples of aromatic hydrocarbon groups in this context include groups obtained by removing one hydrogen atom from the aromatic ring (aryl groups: for example, phenyl groups, naphthyl groups, etc.), and groups in which one of the hydrogen atoms of the aromatic ring is replaced by an alkylene group (for example, benzyl groups, phenethyl groups, 1-naphthylmethyl groups, etc.). The number of carbon atoms in the alkylene group (alkyl chain in the arylalkyl group) is preferably 1 to 4, more preferably 1 to 2, and particularly preferably 1.

[0291] R １０１ The cyclic aliphatic hydrocarbon group in this context refers to an aliphatic hydrocarbon group that contains a ring in its structure. Examples of aliphatic hydrocarbon groups containing a ring in their structure include alicyclic hydrocarbon groups (groups from which one hydrogen atom has been removed from an aliphatic hydrocarbon ring), groups in which an alicyclic hydrocarbon group is bonded to the end of a linear or branched aliphatic hydrocarbon group, and groups in which an alicyclic hydrocarbon group is interposed in the middle of a linear or branched aliphatic hydrocarbon group. The alicyclic hydrocarbon group preferably has 3 to 20 carbon atoms, and more preferably 3 to 12 carbon atoms. The alicyclic hydrocarbon group may be a polycyclic group or a monocyclic group. A preferred monocyclic alicyclic hydrocarbon group is a group from which one or more hydrogen atoms have been removed from a monocycloalkane. The preferred monocycloalkane has 3 to 6 carbon atoms, and specifically includes cyclopentane and cyclohexane. A preferred polycyclic alicyclic hydrocarbon group is a group from which one or more hydrogen atoms have been removed from a polycycloalkane, and the preferred polycycloalkane has 7 to 30 carbon atoms. Among these, the polycycloalkanes include adamantane, norbornane, isobornane, and tricyclo[5.2.1.0 ２，６ Polycycloalkanes having a cross-linked ring system polycyclic skeleton, such as decane and tetracyclododecane; polycycloalkanes having a fused ring system polycyclic skeleton, such as a cyclic group having a steroid skeleton, are more preferred.

[0292] Among them, R １０１As the cyclic aliphatic hydrocarbon group, a group obtained by removing one or more hydrogen atoms from monocycloalkane or polycycloalkane is preferable, a group obtained by removing one hydrogen atom from polycycloalkane is more preferable, an adamantyl group or a norbornyl group is further preferable, and an adamantyl group is particularly preferable.

[0293] The linear aliphatic hydrocarbon group which may be bonded to the alicyclic hydrocarbon group preferably has 1 to 10 carbon atoms, more preferably 1 to 6 carbon atoms, still more preferably 1 to 4 carbon atoms, and most preferably 1 to 3 carbon atoms. As the linear aliphatic hydrocarbon group, a linear alkylene group is preferable. Specifically, methylene group [-CH ２ -), ethylene group [-(CH ２ ) ２ -), trimethylene group [-(CH ２ ) ３ -), tetramethylene group [-(CH ２ ) ４ -), pentamethylene group [-(CH ２ ) ５ -), etc. may be mentioned. The branched aliphatic hydrocarbon group which may be bonded to the alicyclic hydrocarbon group preferably has 2 to 10 carbon atoms, more preferably 3 to 6 carbon atoms, still more preferably 3 or 4 carbon atoms, and most preferably 3 carbon atoms. As the branched aliphatic hydrocarbon group, a branched alkylene group is preferable. Specifically, -CH(CH ３ )-, -CH(CH ２ CH ３ )-, -C(CH ３ ) ２ -, -C(CH ３ )(CH ２ CH ３ )-, -C(CH ３ )(CH ２ CH ２ CH ３ )-, -C(CH ２ CH ３ ) ２ ​​​​​​​​​​​​​２ -, -CH(CH ２ CH ３ )CH ２ -, -C(CH ２ CH ３ ) ２ -CH ２ - Alkyl ethylene groups such as -CH(CH ３ )CH ２ CH ２ -ien-CH ２ CH (CH ３ )CH ２ - Alkyl trimethylene groups such as -CH(CH ３ )CH ２ CH ２ CH ２ -ien-CH ２ CH (CH ３ )CH ２ CH ２ Examples include alkylalkylene groups such as alkyltetramethylene groups. In the alkylalkylene group, a linear alkyl group having 1 to 5 carbon atoms is preferred.

[0294] Also, R １０１ The cyclic hydrocarbon group in may contain heteroatoms, such as heterocycles. Specifically, lactone-containing cyclic groups represented by the general formulas (a2-r-1) to (a2-r-7), and -SO groups represented by the general formulas (b5-r-1) to (b5-r-4), respectively. ２ - Examples include cyclic groups and heterocyclic groups represented by the above chemical formulas (r-hr-1) to (r-hr-16). * in the formula represents Y in formula (b-1). １０１ This represents a coupling that connects to something.

[0295] R １０１Examples of substituents on the cyclic group include alkyl groups, alkoxy groups, halogen atoms, alkyl halides, hydroxyl groups, carbonyl groups, and nitro groups. Preferred alkyl groups as substituents are alkyl groups having 1 to 5 carbon atoms. Preferred alkoxy groups as substituents are alkoxy groups having 1 to 5 carbon atoms. Preferred halogen atoms as substituents are fluorine atoms, bromine atoms, and iodine atoms. Examples of alkyl halides as substituents include alkyl groups having 1 to 5 carbon atoms, such as methyl groups, ethyl groups, propyl groups, n-butyl groups, and tert-butyl groups, in which some or all of the hydrogen atoms are substituted with the halogen atoms. Carbonyl groups as substituents include methylene groups (-CH) that constitute the cyclic hydrocarbon group. ２ It is a substituting group for -).

[0296] R １０１ The cyclic hydrocarbon group in may be a fused ring group containing a fused ring formed by the fusion of an aliphatic hydrocarbon ring and an aromatic ring. Examples of the fused ring include a polycycloalkane having a bridging ring system with one or more aromatic rings fused to it. Specific examples of the bridging ring system polycycloalkane include bicycloalkanes such as bicyclo[2.2.1]heptane (norbornane) and bicyclo[2.2.2]octane. The fused ring group is preferably a group containing a fused ring formed by the fusion of two or three aromatic rings to a bicycloalkane, and more preferably a group containing a fused ring formed by the fusion of two or three aromatic rings to bicyclo[2.2.2]octane. １０１ Specific examples of fused ring groups in this context include the groups represented by the following formulas (r-br-1) to (r-br-2). In the formulas, * represents Y in formula (b-1). １０１ This represents a coupling that connects to something.

[0297]

[0298] R １０１Examples of substituents that the fused ring group in R may have include alkyl groups, alkoxy groups, halogen atoms, alkyl halides, hydroxyl groups, carbonyl groups, nitro groups, aromatic hydrocarbon groups, alicyclic hydrocarbon groups, etc. The alkyl groups, alkoxy groups, halogen atoms, and alkyl halides as substituents of the fused ring group are as described above. １０１ Examples of substituents for cyclic groups in the above are similar to those listed above. Aromatic hydrocarbon groups as substituents for the fused cyclic group include groups obtained by removing one hydrogen atom from an aromatic ring (aryl groups: e.g., phenyl group, naphthyl group, etc.), groups in which one hydrogen atom of the aromatic ring is replaced by an alkylene group (e.g., arylalkyl groups such as benzyl group, phenethyl group, 1-naphthylmethyl group, 2-naphthylmethyl group, 1-naphthylethyl group, 2-naphthylethyl group, etc.), and heterocyclic groups represented by the above formulas (r-hr-1) to (r-hr-6). Alicyclic hydrocarbon groups as substituents for the fused cyclic group include groups obtained by removing one hydrogen atom from monocycloalkanes such as cyclopentane and cyclohexane; adamantane, norbornane, isobornane, tricyclo[5.2.1.0 ２，６ ] Groups obtained by removing one hydrogen atom from polycycloalkanes such as decane and tetracyclododecane; lactone-containing cyclic groups represented by the general formulas (a2-r-1) to (a2-r-7), respectively; -SO groups represented by the general formulas (b5-r-1) to (b5-r-4), respectively. ２ - Containing cyclic groups; examples include heterocyclic groups represented by formulas (r-hr-7) to (r-hr-16), respectively.

[0299] A chain-like alkyl group which may have substituents: R １０１The linear alkyl group may be linear or branched. Linear alkyl groups preferably have 1 to 20 carbon atoms, more preferably 1 to 15, and most preferably 1 to 10. Branched alkyl groups preferably have 3 to 20 carbon atoms, more preferably 3 to 15, and most preferably 3 to 10. Specifically, examples include 1-methylethyl group, 1-methylpropyl group, 2-methylpropyl group, 1-methylbutyl group, 2-methylbutyl group, 3-methylbutyl group, 1-ethylbutyl group, 2-ethylbutyl group, 1-methylpentyl group, 2-methylpentyl group, 3-methylpentyl group, and 4-methylpentyl group.

[0300] A chain-like alkenyl group which may have substituents: R １０１ The linear alkenyl group may be linear or branched, and preferably has 2 to 10 carbon atoms, more preferably 2 to 5, even more preferably 2 to 4, and particularly preferably 3. Examples of linear alkenyl groups include vinyl groups, propenyl groups (allyl groups), and butenyl groups. Examples of branched alkenyl groups include 1-methylvinyl groups, 2-methylvinyl groups, 1-methylpropenyl groups, and 2-methylpropenyl groups. Among the linear alkenyl groups listed above, linear alkenyl groups are preferred, vinyl groups and propenyl groups are more preferred, and vinyl groups are particularly preferred.

[0301] R １０１ Examples of substituents in the chain-like alkyl or alkenyl group include alkoxy groups, halogen atoms, alkyl halides, hydroxyl groups, carbonyl groups, nitro groups, amino groups, and the above R １０１ Examples include cyclic groups in this context.

[0302] In formula (b-1), Y １０１ Y is a single bond or a divalent linking group containing an oxygen atom. １０１ If Y is a divalent linking group containing an oxygen atom, １０１It may contain atoms other than oxygen atoms. Examples of atoms other than oxygen atoms include carbon atoms, hydrogen atoms, sulfur atoms, nitrogen atoms, etc. Examples of the divalent linking group containing an oxygen atom include the linking groups represented by the above general formulas (L - al - 1) to (L - al - 8), respectively.

[0303] In formula (b - 1), V １０１ is a single bond, an alkylene group or a fluorinated alkylene group. The alkylene group and fluorinated alkylene group in V １０１ preferably have 1 to 4 carbon atoms. Among them, V １０１ is preferably a single bond or a linear fluorinated alkylene group having 1 to 4 carbon atoms.

[0304] In formula (b - 1), R １０２ is a fluorine atom or a fluorinated alkyl group having 1 to 5 carbon atoms. R １０２ is preferably a fluorine atom or a perfluoroalkyl group having 1 to 5 carbon atoms, and more preferably a fluorine atom.

[0305] Specific examples of the anion part represented by the formula (b - 1) include, for example, when Y １０１ is a single bond, fluorinated alkyl sulfonate anions such as trifluoromethanesulfonate anion and perfluorobutanesulfonate anion; when Y １０１ is a divalent linking group containing an oxygen atom, anions represented by any of the following formulas (an - 1) to (an - 3) can be mentioned.

[0306] [In the formula, R” １０１ is an aliphatic cyclic group which may have a substituent, a monovalent heterocyclic group represented by the above chemical formulas (r - hr - 1) to (r - hr - 16), a condensed cyclic group represented by the formula (r - br - 1) or (r - br - 2), a chain - like alkyl group which may have a substituent or an aromatic cyclic group which may have a substituent. R” １０２This includes an aliphatic cyclic group which may have substituents, a fused cyclic group represented by formula (r-br-1) or (r-br-2), a lactone-containing cyclic group represented by the general formulas (a2-r-1), (a2-r-3) to (a2-r-7), respectively, or a -SO group represented by the general formulas (b5-r-1) to (b5-r-4), respectively. ２ - Contains a cyclic group. R'' １０３ V'' is an optionally substituted aromatic cyclic group, an optionally substituted aliphatic cyclic group, or an optionally substituted linear alkenyl group. １０１ This is a single bond, an alkylene group having 1 to 4 carbon atoms, or a fluorinated alkylene group having 1 to 4 carbon atoms. １０２ [wherein 'v' is a fluorine atom or a fluorinated alkyl group having 1 to 5 carbon atoms; where 'v' is an independent integer from 0 to 3, where 'q' is an independent integer from 0 to 20, and where 'n' is 0 or 1.]

[0307] R" １０１ , R” １０２ and R” １０３ The aliphatic cyclic group which may have substituents is R in formula (b-1) above. １０１ It is preferable that the substituent is the group exemplified as a cyclic aliphatic hydrocarbon group in formula (b-1). １０１ Examples include substituents similar to those that may be substituted for the cyclic aliphatic hydrocarbon group in the above.

[0308] R" １０１ and R” １０３ The aromatic cyclic group which may have substituents in formula (b-1) is R １０１ It is preferable that the substituent is the group exemplified as an aromatic hydrocarbon group in the cyclic hydrocarbon group in formula (b-1). １０１ Examples include substituents similar to those that may be substituted for the aromatic hydrocarbon group in the above.

[0309] R" １０１ The chain-like alkyl group which may have substituents in formula (b-1) is R １０１ The group exemplified as the chain-like alkyl group in R is preferred. １０３The chain-like alkenyl group which may have substituents in formula (b-1) is R １０１ It is preferable that the group is one of the examples given as a chain-like alkenyl group in the formula.

[0310] • In the anionic formula (b-2) of component (b-2), R １０４ , R １０５ Each of these is independently a cyclic group which may have substituents, a linear alkyl group which may have substituents, or a linear alkenyl group which may have substituents, and each of them is R in formula (b-1). １０１ Similar examples can be given. However, R １０４ , R １０５ They may be bonded to each other to form a ring. １０４ , R １０５ The linear alkyl group is preferably a substituted linear alkyl group, more preferably a linear or branched alkyl group, or a linear or branched fluorinated alkyl group. The number of carbon atoms in the linear alkyl group is preferably 1 to 10, more preferably 1 to 7, and even more preferably 1 to 3. １０４ , R １０５ The number of carbon atoms in the chain-like alkyl group is preferably small within the above range of carbon atoms, for reasons such as good solubility in the resist solvent. １０４ , R １０５ In the chain-like alkyl group, the greater the number of hydrogen atoms substituted with fluorine atoms, the stronger the acidity and the better the transparency to high-energy light and electron beams below 250 nm, which is preferable. The proportion of fluorine atoms in the chain-like alkyl group, i.e., the fluorination rate, is preferably 70 to 100%, more preferably 90 to 100%, and most preferably a perfluoroalkyl group in which all hydrogen atoms are substituted with fluorine atoms. In formula (b-2), V １０２ , V １０３ These are, independently, a single bond, an alkylene group, or a fluorinated alkylene group, and each is V in formula (b-1). １０１ Similar examples can be given. In equation (b-2), L １０１ , L １０２Each of these is either a single bond or an oxygen atom, independently of the others.

[0311] • In the anionic formula (b-3) of component (b-3), R １０６ ~R １０８ Each of these is independently a cyclic group which may have substituents, a linear alkyl group which may have substituents, or a linear alkenyl group which may have substituents, and each of them is R in formula (b-1). １０１ Similar examples can be given. In equation (b-3), L １０３ ~L １０５ These are, independently, single bonds, -CO-, or -SO-. ２ - is the case.

[0312] Among the above, the anion in component (b-1) is preferred as the anion portion of component (B).

[0313] {Cation part} In the above formulas (b-1), (b-2), and (b-3), M' ｍ＋ This represents an m-valent onium cation. Among these, sulfonium cations and iodonium cations are preferred. m is an integer of 1 or more.

[0314] Preferred cation portion ((M' ｍ＋ ) １／ｍ Suitable candidates include cations similar to those represented by the general formulas (ca-1) to (ca-3) above, with the cation represented by the general formula (ca-1) being more preferred, and the cations represented by the formulas (ca-1-1) to (ca-1-84) being even more preferred.

[0315] In the resist composition of this embodiment, component (B) may be used alone or in combination of two or more types. When the resist composition contains component (B), the content of component (B) in the resist composition is preferably less than 50 parts by mass, more preferably 5 to 40 parts by mass, and even more preferably 10 to 40 parts by mass, per 100 parts by mass of component (A1). By setting the content of component (B) within the above preferred range, sufficient pattern formation is achieved. Furthermore, when each component of the resist composition is dissolved in an organic solvent, a uniform solution is easily obtained, which is preferable as it results in good storage stability of the resist composition.

[0316] ≪Basic Component (D)≫ The resist composition of this embodiment may contain a basic component (hereinafter also referred to as "component (D)") that traps (i.e., controls the diffusion of) the acid generated by exposure. Component (D) acts as a quencher (acid diffusion control agent) that traps the acid generated by exposure in the resist composition.

[0317] Examples of component (D) include a photodegradable base (D1) that decomposes upon exposure and loses its ability to control acid diffusion (hereinafter referred to as "component (D1)"), and a nitrogen-containing organic compound (D2) that does not fall under component (D1) (hereinafter referred to as "component (D2)"). Among these, a photodegradable base (component (D1)) is preferred because it is easy to improve sensitivity, reduce surface roughness of the pattern, improve in-plane uniformity of pattern dimensions (CDU), and enhance fine resolution. Compounds exemplified as component (D1) described later may be used as the acid-generating agent component (component (B)) described above, depending on the combination with other compounds.

[0318] Regarding component (D1): Component (D1) is not particularly limited as long as it decomposes upon exposure and loses its acid diffusion controllability. Preferably, it is one or more compounds selected from the group consisting of the compound represented by the following general formula (d1-1) (hereinafter referred to as "component (d1-1)"), the compound represented by the following general formula (d1-2) (hereinafter referred to as "component (d1-2)"), and the compound represented by the following general formula (d1-3) (hereinafter referred to as "component (d1-3)"). Components (d1-1) to (d1-3) do not act as quenchers in the exposed areas of the resist film because they decompose and lose their acid diffusion controllability (basicity), but they act as quenchers in the unexposed areas of the resist film.

[0319] [In the formula, Rd １ ~Rd ４ Rd in formula (d1-2) is a cyclic group which may have substituents, a linear alkyl group which may have substituents, or a linear alkenyl group which may have substituents. ２ In this example, assume that no fluorine atoms are bonded to the carbon atoms adjacent to the sulfur atom. １is a single bond or a divalent linking group. m is an integer of 1 or more, M ｍ＋ These are each independently m-valent cations.

[0320] {(d1-1) component} ... in the anionic component of formula (d1-1), Rd １ R' is a cyclic group which may have substituents, a linear alkyl group which may have substituents, or a linear alkenyl group which may have substituents, and each of the above R' is... ２０１ Similar examples include Rd １ Preferred substituents are optionally substituted aromatic hydrocarbon groups, optionally substituted aliphatic cyclic groups, or optionally substituted linear alkyl groups. Examples of substituents these groups may have include hydroxyl groups, oxo groups, alkyl groups, aryl groups, fluorine atoms, fluorinated alkyl groups, lactone-containing cyclic groups represented by the general formulas (a2-r-1) to (a2-r-7), ether bonds, ester bonds, or combinations thereof. When ether bonds or ester bonds are included as substituents, they may be mediated via alkylene groups, and preferred substituents in this case are the linking groups represented by the formulas (L-al-1) to (L-al-5) and (L-al-8), respectively. Note that Rd １ If the aromatic hydrocarbon group, aliphatic cyclic group, or linear alkyl group in has a linking group represented by the general formulas (L-al-1) to (L-al-8) as a substituent, then in the general formulas (L-al-1) to (L-al-8), Rd in formula (d1-1) １ The carbon atom constituting the aromatic hydrocarbon group, aliphatic cyclic group, or chain-like alkyl group in the above general formula (L-al-1) to (L-al-8) is bonded to the carbon atom. １０１ The aromatic hydrocarbon group can be preferably a phenyl group, a naphthyl group, or a polycyclic structure containing a bicyclooctane skeleton (a polycyclic structure consisting of a bicyclooctane skeleton and other ring structures). The aliphatic cyclic group can be adamantane, norbornane, isobornane, or tricyclo[5.2.1.0 ２，６It is more preferable that the group is obtained by removing one or more hydrogen atoms from a polycycloalkane such as decane or tetracyclododecane. The chain-like alkyl group is preferably one to ten carbon atoms in number, and specifically, examples include linear alkyl groups such as methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, heptyl group, octyl group, nonyl group, and decyl group; and branched alkyl groups such as 1-methylethyl group, 1-methylpropyl group, 2-methylpropyl group, 1-methylbutyl group, 2-methylbutyl group, 3-methylbutyl group, 1-ethylbutyl group, 2-ethylbutyl group, 1-methylpentyl group, 2-methylpentyl group, 3-methylpentyl group, and 4-methylpentyl group.

[0321] When the chain-like alkyl group is a fluorinated alkyl group having a fluorinated alkyl group as a substituent, the number of carbon atoms in the fluorinated alkyl group is preferably 1 to 11, more preferably 1 to 8, and even more preferably 1 to 4. The fluorinated alkyl group may contain atoms other than fluorine. Examples of atoms other than fluorine include oxygen atoms, sulfur atoms, nitrogen atoms, and the like.

[0322] The following are preferred specific examples of the anion portion of component (d1-1).

[0323]

[0324] ...In the cation component (d1-1), M ｍ＋ M is a cation with an m-valence. ｍ＋ Suitable cations include those similar to those represented by the general formulas (ca-1) to (ca-3), with the cation represented by the general formula (ca-1) being more preferred, and the cations represented by the formulas (ca-1-1) to (ca-1-84) being even more preferred. The (d1-1) component may be used alone or in combination of two or more types.

[0325] {(d1-2) component} ... in the anionic component of formula (d1-2), Rd ２ R' is a cyclic group which may have substituents, a linear alkyl group which may have substituents, or a linear alkenyl group which may have substituents.２０１ Similar examples include the following. However, Rd ２ In this case, the carbon atom adjacent to the S atom is assumed to be unbonded to a fluorine atom (not fluorine-substituted). This results in the anions of components (d1-2) becoming appropriately weak acid anions, improving the quenching ability of component (D). Rd ２ The alkyl group is preferably a chain-like alkyl group which may have substituents, or an aliphatic cyclic group which may have substituents, and more preferably an aliphatic cyclic group which may have substituents.

[0326] The linear alkyl group preferably has 1 to 10 carbon atoms, and more preferably 3 to 10 carbon atoms. The aliphatic cyclic group may be adamantane, norbornane, isobornane, or tricyclo[5.2.1.0 ２，６ A group obtained by removing one or more hydrogen atoms from decane, tetracyclododecane, etc. (which may have substituents); more preferably a group obtained by removing one or more hydrogen atoms from camphor.

[0327] Rd ２ The hydrocarbon group may have substituents, and such substituents may be Rd of formula (d1-1). １ Examples include substituents similar to those that may be present on hydrocarbon groups (aromatic hydrocarbon groups, aliphatic cyclic groups, and linear alkyl groups) in the above.

[0328] The following are preferred specific examples of the anion portion of component (d1-2).

[0329]

[0330] ...In the cation component formula (d1-2), M ｍ＋ is an m-valent cation, and M in formula (d1-1) ｍ＋ The same applies. (d1-2) Components may be used individually or in combination of two or more.

[0331] {(d1-3) component} ... in the anionic component of formula (d1-3), Rd ３R' is a cyclic group which may have substituents, a linear alkyl group which may have substituents, or a linear alkenyl group which may have substituents, and the R' ２０１ Similar groups are mentioned, and it is preferable that they are cyclic groups containing a fluorine atom, linear alkyl groups, or linear alkenyl groups. Among these, fluorinated alkyl groups are preferred, and the aforementioned Rd １ A fluorinated alkyl group similar to the one shown is more preferable.

[0332] In formula (d1-3), Rd ４ R' is a cyclic group which may have substituents, a linear alkyl group which may have substituents, or a linear alkenyl group which may have substituents. ２０１ Similar examples include alkyl groups, alkoxy groups, alkenyl groups, and cyclic groups, which may have substituents. Rd ４ The alkyl group in is preferably a linear or branched alkyl group having 1 to 5 carbon atoms. Specifically, examples include methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, isobutyl group, tert-butyl group, pentyl group, isopentyl group, neopentyl group, etc. ４ Some of the hydrogen atoms in the alkyl group may be substituted with hydroxyl groups, cyano groups, etc. Rd ４ The alkoxy group in is preferably an alkoxy group having 1 to 5 carbon atoms. Specifically, examples of alkoxy groups having 1 to 5 carbon atoms include methoxy, ethoxy, n-propoxy, iso-propoxy, n-butoxy, and tert-butoxy groups. Among these, methoxy and ethoxy groups are preferred.

[0333] Rd ４ The alkenyl group in R' is ２０１ Examples of groups similar to the alkenyl group in the above include vinyl groups, propenyl groups (allyl groups), 1-methylpropenyl groups, and 2-methylpropenyl groups, which are preferred. These groups may further have substituents of an alkyl group having 1 to 5 carbon atoms or a halogenated alkyl group having 1 to 5 carbon atoms.

[0334] Rd ４ The cyclic group in is R' ２０１Examples of cyclic groups similar to those in [5.2.1.0] include cyclopentane, cyclohexane, adamantane, norbornane, isobornane, and tricyclo[5.2.1.0]. ２，６ A preferred alicyclic group is obtained by removing one or more hydrogen atoms from a cycloalkane such as decane or tetracyclododecane, or an aromatic group such as a phenyl group or naphthyl group. ４ When Rd is an alicyclic group, the resist composition dissolves well in organic solvents, resulting in good lithography properties. ４ When the resist group is an aromatic group, in lithography using EUV or the like as the exposure light source, the resist composition exhibits excellent light absorption efficiency, resulting in good sensitivity and lithographic characteristics.

[0335] In formula (d1-3), Yd １ Yd is a single bond or a divalent linking group. １ The divalent linking group in formula (a2-1) is not particularly limited, but may include divalent hydrocarbon groups (aliphatic hydrocarbon groups, aromatic hydrocarbon groups) which may have substituents, and divalent linking groups containing heteroatoms. ２１ Examples of divalent linking groups include divalent hydrocarbon groups that may have substituents, and divalent linking groups containing heteroatoms, as mentioned in the explanation of divalent linking groups in Yd. １ The preferred members are carbonyl groups, ester bonds, amide bonds, alkylene groups, or combinations thereof. The alkylene group is more preferably a linear or branched alkylene group, and even more preferably a methylene group or an ethylene group.

[0336] The following are preferred specific examples of the anionic portions of components (d1-3).

[0337]

[0338]

[0339] ...In the cation component formula (d1-3), M ｍ＋ is an m-valent cation, and M in formula (d1-1) ｍ＋The same applies. (d1-3) Components may be used individually or in combination of two or more.

[0340] The (D1) component may be any one of the above components (d1-1) to (d1-3), or two or more may be used in combination. When the resist composition contains the (D1) component, the content of the (D1) component in the resist composition is preferably 0.5 to 15 parts by mass, more preferably 1 to 12 parts by mass, and even more preferably 2 to 10 parts by mass, per 100 parts by mass of the (A1) component.

[0341] Component (D1) preferably contains component (d1-1) as described above. The content of component (d1-1) in the total component (D1) is preferably 50% by mass or more, preferably 70% by mass or more, and more preferably 90% by mass or more, and component (D1) may consist only of compound (d1-1).

[0342] Method for producing component (D1): The methods for producing components (d1-1) and (d1-2) described above are not particularly limited and can be produced by known methods. The method for producing component (d1-3) is also not particularly limited and can be produced, for example, in the same manner as described in US2012-0149916.

[0343] Regarding component (D2): Component (D) may contain nitrogen-containing organic compound components that do not fall under component (D1) above (hereinafter referred to as "component (D2)"). Component (D2) is not particularly limited as long as it acts as an acid diffusion control agent and does not fall under component (D1), and any known component may be used. Among these, aliphatic amines are preferred, and among these, secondary aliphatic amines and tertiary aliphatic amines are more preferred. An aliphatic amine is an amine having one or more aliphatic groups, and it is preferable that the aliphatic group has 1 to 12 carbon atoms. Examples of aliphatic amines include ammonia (NH) ３Examples include amines (alkylamines or alkyl alcoholamines) or cyclic amines in which at least one hydrogen atom is substituted with an alkyl group or hydroxyalkyl group having 12 or fewer carbon atoms. Specific examples of alkylamines and alkyl alcoholamines include monoalkylamines such as n-hexylamine, n-heptylamine, n-octylamine, n-nonylamine, and n-decylamine; dialkylamines such as diethylamine, di-n-propylamine, di-n-heptylamine, di-n-octylamine, and dicyclohexylamine; trialkylamines such as trimethylamine, triethylamine, tri-n-propylamine, tri-n-butylamine, tri-n-pentylamine, tri-n-hexylamine, tri-n-heptylamine, tri-n-octylamine, tri-n-nonylamine, tri-n-decylamine, and tri-n-dodecylamine; and alkyl alcoholamines such as diethanolamine, triethanolamine, diisopropanolamine, triisopropanolamine, di-n-octanolamine, and tri-n-octanolamine. Among these, trialkylamines having 6 to 30 carbon atoms are more preferred, and tri-n-pentylamine or tri-n-octylamine are particularly preferred.

[0344] Examples of cyclic amines include heterocyclic compounds containing a nitrogen atom as a heteroatom. These heterocyclic compounds may be monocyclic (aliphatic monocyclic amines) or polycyclic (aliphatic polycyclic amines). Specific examples of aliphatic monocyclic amines include piperidine and piperazine. Aliphatic polycyclic amines with 6 to 10 carbon atoms are preferred, and specific examples include 1,5-diazabicyclo[4.3.0]-5-nonene, 1,8-diazabicyclo[5.4.0]-7-undecene, hexamethylenetetramine, and 1,4-diazabicyclo[2.2.2]octane.

[0345] Other aliphatic amines include tris(2-methoxymethoxyethyl)amine, tris{2-(2-methoxyethoxy)ethyl}amine, tris{2-(2-methoxyethoxymethoxy)ethyl}amine, tris{2-(1-methoxyethoxy)ethyl}amine, tris{2-(1-ethoxyethoxy)ethyl}amine, tris{2-(1-ethoxypropoxy)ethyl}amine, tris[2-{2-(2-hydroxyethoxy)ethoxy}ethyl]amine, triethanolamine triacetate, etc., with triethanolamine triacetate being preferred.

[0346] Furthermore, an aromatic amine may be used as component (D2). Examples of aromatic amines include 4-dimethylaminopyridine, pyrrole, indole, pyrazole, imidazole or derivatives thereof, tripenzylamine, 2,6-diisopropylaniline, N-tert-butoxycarbonylpyrrolidine, and 2,6-di-tert-butylpyridine.

[0347] The (D2) component may be used alone or in combination of two or more types. When the resist composition contains the (D2) component, the content of the (D2) component in the resist composition is usually in the range of 0.01 to 5 parts by mass per 100 parts by mass of the (A1) component. By using the above range, the resist pattern shape, settling stability over time, etc., are improved.

[0348] <<At least one compound (E) selected from the group consisting of organic carboxylic acids and phosphorus oxoacids and their derivatives>> The resist composition of this embodiment may contain, as an optional component, at least one compound (E) selected from the group consisting of organic carboxylic acids and phosphorus oxoacids and their derivatives (hereinafter referred to as "component (E)"). Specifically, examples of organic carboxylic acids include acetic acid, malonic acid, citric acid, malic acid, succinic acid, benzoic acid, salicylic acid, etc., with salicylic acid being preferred among them. Examples of phosphorus oxoacids include phosphoric acid, phosphonic acid, phosphinic acid, etc., with phosphonic acid being particularly preferred among these.

[0349] In the resist composition of this embodiment, component (E) may be used alone or in combination of two or more types. When the resist composition contains component (E), the content of component (E) is preferably 0.01 to 5 parts by mass, and more preferably 0.05 to 3 parts by mass, per 100 parts by mass of component (A1). By setting it within the above range, the lithography characteristics are further improved.

[0350] ≪Fluorine Additive Component (F)≫ The resist composition of this embodiment may contain a fluorine additive component (hereinafter referred to as "component (F)") as a hydrophobic resin. Component (F) is used to impart water repellency to the resist film and, when used as a resin separate from component (A), can improve lithography properties. As component (F), for example, fluorine-containing polymer compounds described in Japanese Patent Publication No. 2010-002870, Japanese Patent Publication No. 2010-032994, Japanese Patent Publication No. 2010-277043, Japanese Patent Publication No. 2011-13569, and Japanese Patent Publication No. 2011-128226 can be used. More specifically as component (F), polymers having a constituent unit (f1) represented by the following general formula (f1-1) can be mentioned. The polymer is preferably a polymer (homopolymer) consisting only of a constituent unit (f1) represented by the following formula (f1-1); a copolymer of the constituent unit (f1) and the constituent unit (a1); and more preferably a copolymer of the constituent unit (f1) and a constituent unit derived from acrylic acid or methacrylic acid and the constituent unit (a1). Here, the constituent unit (a1) copolymerized with the constituent unit (f1) is preferably a constituent unit derived from 1-ethyl-1-cyclooctyl (meth)acrylate, a constituent unit derived from 1-methyl-1-adamantyl (meth)acrylate, and more preferably a constituent unit derived from 1-ethyl-1-cyclooctyl (meth)acrylate.

[0351] [In the formula, R is the same as above, Rf １０２ and Rf １０３Each of these independently represents a hydrogen atom, a halogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms, and Rf １０２ and Rf １０３ They may be the same or different. １ Rf is an integer between 0 and 5. １０１ It is an organic group containing a fluorine atom.

[0352] In formula (f1-1), R bonded to the carbon atom at the α position is the same as described above. R is preferably a hydrogen atom or a methyl group. In formula (f1-1), Rf １０２ and Rf １０３ A fluorine atom is preferred as the halogen atom. Rf １０２ and Rf １０３ Examples of alkyl groups having 1 to 5 carbon atoms in R include those similar to the alkyl groups having 1 to 5 carbon atoms in R above, with methyl or ethyl groups being preferred. １０２ and Rf １０３ Specifically, examples of halogenated alkyl groups having 1 to 5 carbon atoms include groups in which some or all of the hydrogen atoms of the alkyl group having 1 to 5 carbon atoms are substituted with halogen atoms. Fluorine atoms are preferred as the halogen atoms, particularly Rf. １０２ and Rf １０３ Preferably, the atoms are hydrogen atoms, fluorine atoms, or alkyl groups having 1 to 5 carbon atoms; more preferably, hydrogen atoms, fluorine atoms, methyl groups, or ethyl groups; and even more preferably, hydrogen atoms. In formula (f1-1), nf １ x is an integer between 0 and 5, preferably between 0 and 3, and more preferably 1 or 2.

[0353] In formula (f1-1), Rf １０１The fluorine atom is an organic group containing a fluorine atom, and preferably a hydrocarbon group containing a fluorine atom. The hydrocarbon group containing a fluorine atom may be linear, branched, or cyclic, and preferably has 1 to 20 carbon atoms, more preferably 1 to 15 carbon atoms, and particularly preferably 1 to 10 carbon atoms. Furthermore, it is preferable that 25% or more of the hydrogen atoms in the hydrocarbon group are fluorinated, more preferably 50% or more, and particularly preferable that 60% or more are fluorinated, as this increases the hydrophobicity of the resist film during immersion exposure. Among these, Rf １０１ More preferably, it is a fluorinated hydrocarbon group having 1 to 6 carbon atoms, a trifluoromethyl group, or -CH ２ -CF ３ ien-CH ２ -CF ２ -CF ３ , -CH(CF ３ ) ２ ien-CH ２ -CH ２ -CF ３ ien-CH ２ -CH ２ -CF ２ -CF ２ -CF ２ -CF ３ That is particularly preferable.

[0354] The weight-average molecular weight (Mw) of component (F) (based on polystyrene conversion by gel permeation chromatography) is preferably 1,000 to 50,000, more preferably 5,000 to 40,000, and most preferably 10,000 to 30,000. If it is below the upper limit of this range, it has sufficient solubility in the resist solvent for use as a resist, and if it is above the lower limit of this range, the water repellency of the resist film is good. The dispersion degree (Mw / Mn) of component (F) is preferably 1.0 to 5.0, more preferably 1.0 to 3.0, and most preferably 1.0 to 2.5.

[0355] In the resist composition of this embodiment, component (F) may be used alone or in combination of two or more types. When the resist composition contains component (F), the content of component (F) is preferably 0.5 to 10 parts by mass, and more preferably 1 to 10 parts by mass, per 100 parts by mass of component (A1).

[0356] ≪Organic Solvent Component (S)≫ The resist composition of this embodiment can be manufactured by dissolving the resist material in an organic solvent component (hereinafter referred to as "component (S)"). In the resist composition of this embodiment, component (S) may be used alone or as a mixture of two or more solvents. Among these, propylene glycol monomethyl ether acetate (PGMEA), propylene glycol monomethyl ether (PGME), γ-butyrolactone, ethyl lactate (EL), and cyclohexanone are preferred.

[0357] Furthermore, a mixed solvent obtained by mixing PGMEA and a polar solvent is also preferred as component (S). The mixing ratio (mass ratio) can be appropriately determined considering the compatibility between PGMEA and the polar solvent. A mixed solvent of at least one selected from PGMEA and EL and γ-butyrolactone is also preferred as component (S). In this case, the mixing ratio is preferably 70:30 to 95:5 in mass ratio. The amount of component (S) used is not particularly limited and is appropriately set according to the coating thickness at a concentration that can be applied to a substrate, etc. Generally, component (S) is used so that the solid content concentration of the resist composition is in the range of 0.1 to 20% by mass, preferably 0.2 to 15% by mass.

[0358] The resist composition of this embodiment may be prepared by dissolving the resist material in component (S), and then removing impurities using a porous polyimide membrane, a porous polyamide-imide membrane, or the like. For example, the resist composition may be filtered using a filter made of a porous polyimide membrane, a filter made of a porous polyamide-imide membrane, or a filter made of a porous polyimide membrane and a porous polyamide-imide membrane. Examples of the porous polyimide membrane and the porous polyamide-imide membrane include those described in Japanese Patent Application Publication No. 2016-155121.

[0359] As described above, the resist composition of this embodiment contains a polymer (A1-0) in which a linking group represented by the general formula (a0-L) constitutes part of the polymer main chain. This polymer (A1-0) decomposes when the linking group is split into two by the action of an acid. Therefore, in resist pattern formation, in the resist film exposure area, the decomposition of the polymer main chain reduces the Mw of the polymer, improving the solubility of the polymer in the developer. On the other hand, the Mw of the polymer forming the unexposed resist film remains unchanged, and the difference in Mw of the polymer forming the resist film between the exposed and unexposed resist film areas increases the difference in dissolution contrast in the developer. In addition, since the Mw of the polymer forming the resist film can be made different between the exposed and unexposed resist film areas, it is easier to suppress the dissolution of the unexposed resist film area in the developer. These effects work synergistically, so that with the resist composition of this embodiment, high sensitivity can be achieved in resist pattern formation, the effect of roughness reduction can be enhanced, and film thinning can be further suppressed.

[0360] (Method for forming a resist pattern) One embodiment of the resist pattern forming method according to the second aspect is a resist pattern forming method comprising the steps of forming a resist film on a support using one embodiment of the resist composition described above, exposing the resist film, and developing the exposed resist film to form a resist pattern.

[0361] First, the resist composition of the above-described embodiment is applied onto a support using a spinner or the like, and a bake (post-application bake (PAB)) treatment is performed for 40 to 120 seconds, preferably 60 to 90 seconds, at a temperature of, for example, 80 to 150°C, to form a resist film. Next, the resist film is subjected to selective exposure using an exposure apparatus such as an electron beam lithography apparatus or an ArF exposure apparatus, either through exposure via a mask (mask pattern) with a predetermined pattern formed on it or by direct irradiation with an electron beam without a mask pattern, and then a bake (post-exposure bake (PEB)) treatment is performed for 40 to 120 seconds, preferably 60 to 90 seconds, at a temperature of, for example, 80 to 150°C. Next, the resist film is subjected to a development treatment. In the case of an alkaline development process, an alkaline developer is used, and in the case of a solvent development process, a developer containing an organic solvent (organic developer) is used.

[0362] After development, rinsing is preferably performed. In the case of an alkaline development process, rinsing with pure water is preferred, and in the case of a solvent development process, rinsing with a rinsing solution containing an organic solvent is preferred. In the case of a solvent development process, after the development or rinsing process, the developer or rinsing solution adhering to the pattern may be removed using a supercritical fluid. After development or rinsing, drying is performed. In some cases, baking (post-baking) may be performed after the development process.

[0363] The support material is not particularly limited and can be any conventionally known material, such as a substrate for electronic components or a substrate on which a predetermined wiring pattern has been formed. More specifically, examples include silicon wafers, metal substrates such as copper, chromium, iron, and aluminum, and glass substrates. As for the wiring pattern material, for example, copper, aluminum, nickel, and gold can be used.

[0364] The wavelength used for exposure is not particularly limited, and exposure can be performed using ArF excimer lasers, KrF excimer lasers, or F ２This can be carried out using radiation such as excimer lasers, EUV (extreme ultraviolet), VUV (vacuum ultraviolet), EB (electron beam), X-rays, and soft X-rays. The resist pattern formation method of this embodiment is a method that is suitable for exposing the resist film with EUV (extreme ultraviolet) or EB (electron beam) in the step of exposing the resist film.

[0365] The method for exposing a resist film may be conventional exposure (dry exposure) performed in an inert gas such as air or nitrogen, or it may be liquid immersion lithography. Liquid immersion lithography is an exposure method in which the space between the resist film and the lens at the lowest position of the exposure apparatus is filled in advance with a solvent (liquid immersion medium) having a refractive index greater than that of air, and exposure (immersion exposure) is performed in that state. The liquid immersion medium is preferably a solvent having a refractive index greater than that of air and smaller than that of the resist film to be exposed. Examples include water, fluorinated inert liquids, silicon-based solvents, and hydrocarbon-based solvents. Among these, water is preferably used as the liquid immersion medium.

[0366] Examples of alkaline developers used in the alkaline development process include 0.1 to 10% by mass of tetramethylammonium hydroxide (TMAH) aqueous solution. The organic solvent contained in the organic developer used in the solvent development process can be any solvent that can dissolve component (A) (component (A) before exposure), and can be appropriately selected from known organic solvents. Specifically, examples include polar solvents such as ketone solvents, ester solvents, alcohol solvents, nitrile solvents, amide solvents, and ether solvents, as well as hydrocarbon solvents.

[0367] Examples of ester solvents include methyl acetate, butyl acetate, ethyl acetate, isopropyl acetate, pentyl acetate, isopentyl acetate, amyl acetate, propylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, diethylene glycol monobutyl ether acetate, diethylene glycol monoethyl ether acetate, ethyl-3-ethoxypropionate, 3-methoxybutyl acetate, 3-methyl-3-methoxybutyl acetate, methyl formate, ethyl formate, butyl formate, propyl formate, ethyl lactate, butyl lactate, propyl lactate, butyl butanoate, methyl 2-hydroxyisobutyrate, isoamyl acetate, isobutyl isobutyrate, and butyl propionate.

[0368] Examples of nitrile solvents include acetonitrile, propionitrile, valeronitrile, and butyronitrile.

[0369] Organic developers may contain known additives as needed. Examples of such additives include surfactants.

[0370] The development process can be carried out by known development methods, such as immersing the support in developer for a certain period of time (dip method), piling up developer on the surface of the support by surface tension and leaving it still for a certain period of time (paddle method), spraying developer onto the surface of the support (spray method), or continuously dispensing developer onto a support rotating at a constant speed while scanning the developer dispensing nozzle at a constant speed (dynamic dispensing method).

[0371] As the organic solvent contained in the rinsing solution used for rinsing after development in the solvent development process, for example, organic solvents that do not easily dissolve the resist pattern can be appropriately selected and used from among the organic solvents listed as organic solvents used in the organic developer solution. Typically, at least one solvent selected from hydrocarbon solvents, ketone solvents, ester solvents, alcohol solvents, amide solvents, and ether solvents is used. These organic solvents may be used individually or in combination of two or more. They may also be used in mixture with other organic solvents or water.

[0372] Rinsing (cleaning) using a rinsing solution can be carried out by known rinsing methods. Examples of such rinsing methods include continuously applying the rinsing solution onto a support rotating at a constant speed (rotary coating method), immersing the support in the rinsing solution for a certain period of time (dip method), and spraying the rinsing solution onto the surface of the support (spray method).

[0373] According to the resist pattern formation method of the embodiment described above, since the resist composition of the embodiment described above is used, high sensitivity can be achieved in resist pattern formation, lithography characteristics such as roughness reduction can be enhanced, and a resist pattern with a good shape can be formed with further suppression of film loss.

[0374] The resist compositions of the embodiments described above, and the various materials used in the resist pattern formation method of the embodiments described above (for example, resist solvent, developer, rinse solution, anti-reflective film forming composition, top coat forming composition, etc.) are preferably free of impurities such as metals, metal salts containing halogens, acids, alkalis, sulfur atoms, or phosphorus atoms. Examples of metal atom-containing impurities include Na, K, Ca, Fe, Cu, Mn, Mg, Al, Cr, Ni, Zn, Ag, Sn, Pb, Li, or salts thereof. The content of impurities in these materials is preferably 200 ppb or less, more preferably 1 ppb or less, even more preferably 100 ppt (parts per trillion) or less, particularly preferably 10 ppt or less, and most preferably substantially free (below the detection limit of the measuring device).

[0375] (Polymer) One embodiment of the polymer according to the third aspect is a polymer in which a linking group represented by the following general formula (a0-L) constitutes part of the polymer main chain. Such a linking group is characterized by having an ester bond (-C(=O)-O-) and a thiol residue (-S-) in symmetrical positions.

[0376] [In the formula, R １０ R represents a hydrocarbon group whose linking group is split into two by the action of an acid.２０ and R ３０ *1 and *2 each independently represent alkylene groups with 1 to 5 carbon atoms. *1 and *2 each represent bonds attached to the polymer main chain. O is an oxygen atom. S is a sulfur atom.

[0377] In the polymer of this embodiment, R in the general formula (a0-L) １０ Preferably, the hydrocarbon group is one in which at least one carbon atom (C*) bonded to -C(=O)-O- is a tertiary carbon atom, or a hydrocarbon group in which the carbon atom (C*) is a secondary carbon atom.

[0378] In the polymer of this embodiment, a polymer compound is formed in which a first copolymer is bonded to the bond side *1 and a second copolymer is bonded to the bond side *2 via the linking group, and it is preferable that the first copolymer and the second copolymer each contain a copolymer having a repeating structure of a constituent unit (a1) containing an acid-degradable group whose polarity increases by the action of an acid, and a constituent unit (a10) represented by the following general formula (a10-1).

[0379] [In the formula, R is an alkyl group having 1 to 5 carbon atoms, an alkyl halide having 1 to 5 carbon atoms, or a hydrogen atom. Ya ｘ１ This is a divalent linking group or a single bond. Wa ｘ１ n is an aromatic hydrocarbon group which may have substituents. ａｘ１ [ is an integer greater than or equal to 1.]

[0380] In the polymer of this embodiment, a weight-average molecular weight of 4,000 or more and 12,000 or less is preferred. Details of the polymer according to the third embodiment are the same as those described above for component (A1-0).

[0381] [Method for producing polymers] Polymers in which a linking group represented by the general formula (a0-L) constitutes part of the polymer main chain can be produced using known production methods.

[0382] For example, monomers that induce each constituent unit of a polymer, and "HS-R" as a chain transfer agent. ２０By dissolving "-C(=O)-OH" in a polymerization solvent and polymerizing it, a terminal group "-S-R" is formed at at least one end of the main chain. ２０ A polymer (A1-01) having "-C(=O)-OH" is obtained.

[0383] Next, the polymer (A1-01) and the diol "HO-R" １０ The -OH group is reacted with a condensing agent. This yields the desired polymer, in which polymer (A1-01) is bonded to bond site *1 and bond site *2 via a linking group represented by the general formula (a0-L). After this, depending on the monomer that derives the constituent units, the desired polymer can also be obtained by performing a deprotection reaction, a salt exchange reaction, etc. Examples of condensing agents that can be used here include dicyclohexylcarbodiimide, diisopropylcarbodiimide (DIC), 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride, and carbonyldiimidazole (CDI).

[0384] In the polymer of this embodiment described above, the polymer main chain decomposes when the linking group is split into two by the action of an acid. When the polymer of this embodiment is used in a resist composition, in resist pattern formation, the polymer main chain decomposes in the resist film exposure area, so the Mw of the polymer decreases and the solubility of the polymer in the developer improves. On the other hand, the Mw of the polymer forming the unexposed resist film area remains unchanged, and the difference in Mw of the polymer forming the resist film between the exposed and unexposed resist film areas results in a large difference in solubility contrast in the developer. Thus, the polymer of this embodiment can be used as a resin component of a resist composition according to the first embodiment. Furthermore, polymer compounds in which copolymers having a repeating structure of constituent unit (a1) and constituent unit (a10) are linked together via the linking group are particularly suitable as resist materials for lithography exposed to EUV or EB.

[0385] The present invention will be described below with reference to examples, but the present invention is not limited to the following examples.

[0386] <Production of Polymers> [Synthesis of Polymer (A)-1] 13.2 g of compound (a10-1pre), 11.6 g of compound (a1-1m), and 1.6 g of compound (Z1-1) as a chain transfer agent were dissolved in 130 g of methyl ethyl ketone (MEK), heated to 70°C under a nitrogen atmosphere, and stirred for 5 hours to allow the reaction to proceed. After the reaction was complete, the resulting reaction solution was precipitated in 600 g of heptane and washed.

[0387]

[0388] The obtained white solid was again dissolved in 70 g of methyl ethyl ketone (MEK), and 3.0 g of 1,1'-carbonyldiimidazole and 1.0 g of 1,4-cyclohexendiol were added. The mixture was stirred at 60°C for 4 hours to obtain the reaction solution.

[0389]

[0390] Subsequently, 4.2 g of acetic acid and 80 g of methanol (MeOH) were added to the reaction solution, and a deprotection reaction was carried out at 30°C for 18 hours. After the reaction was complete, the resulting reaction solution was precipitated in 600 g of heptane and washed. The resulting white solid was filtered and dried under reduced pressure overnight to obtain polymer (A)-1 of the target product.

[0391]

[0392] [Synthesis of Polymers (A)-2 to (A)-8] Polymers (A)-2 to (A)-8 were obtained by the same method as in [Synthesis of Polymer (A)-1] above, except that the following diols (2) to (8) were used instead of 1,4-cyclohexenediol.

[0393]

[0394] [Synthesis of Polymer (A)-9] Polymer (A)-9 was obtained by the same method as in [Synthesis of Polymer (A)-1] above, except that compound (Z1-2) below was used instead of compound (Z1-1) as a chain transfer agent.

[0395]

[0396] [Synthesis of Polymer (A)-10 and Polymer (A)-11] Polymer (A)-10 was obtained by the same method as in [Synthesis of Polymer (A)-1] above, except that compound (a1-2m) was used instead of compound (a1-1m). Polymer (A)-11 was obtained by the same method as in [Synthesis of Polymer (A)-1] above, except that compound (a1-3m) was used instead of compound (a1-1m).

[0397]

[0398] [Synthesis of Polymer (A)-12 and Polymer (A)-13] Polymer (A)-12 was obtained by the same method as in [Synthesis of Polymer (A)-1], except that compound (a5-1m) was used in addition to compound (a10-1pre) and compound (a1-1m). Polymer (A)-13 was obtained by the same method as in [Synthesis of Polymer (A)-1], except that compound (a5-1m) and compound (a6-1m) were used in addition to compound (a10-1pre) and compound (a1-1m).

[0399]

[0400] The structures of the synthesized polymers (A)-1 to (A)-13 are shown below. For each polymer, the weight-average molecular weight (Mw), molecular weight dispersion (Mw / Mn) in terms of standard polystyrene, and the structure of the synthesized polymers (A)-1 to (A)-13 are shown below. １３ The copolymerization composition ratio (the proportion (molar ratio) of each constituent unit in the structural formula) determined by 13C NMR is shown. In chemical formulas (A)-1 to (A)-13, the brackets [] indicate a part of the polymer main chain structure, and copolymers consisting of repeating structures of each constituent unit are bonded to both sides of the brackets.

[0401]

[0402] (A)-1: A polymer represented by chemical formula (A)-1. The weight-average molecular weight (Mw) on a standard polystyrene basis, determined by GPC measurement, was 7300, and the molecular weight dispersion (Mw / Mn) was 1.53. １３The copolymerization ratio (the proportion (molar ratio) of each constituent unit in the structural formula) determined by C-NMR was l / m = 60 / 40.

[0403] (A)-2: A polymer represented by chemical formula (A)-2. The weight-average molecular weight (Mw) on a standard polystyrene basis, determined by GPC measurement, was 7200, and the molecular weight dispersion (Mw / Mn) was 1.71. １３ The copolymerization ratio (the proportion (molar ratio) of each constituent unit in the structural formula) determined by C-NMR was l / m = 60 / 40.

[0404] (A)-3: A polymer represented by chemical formula (A)-3. The weight-average molecular weight (Mw) on a standard polystyrene basis, determined by GPC measurement, was 6900, and the molecular weight dispersion (Mw / Mn) was 1.58. １３ The copolymerization ratio (the proportion (molar ratio) of each constituent unit in the structural formula) determined by C-NMR was l / m = 60 / 40.

[0405] (A)-4: A polymer represented by chemical formula (A)-4. The weight-average molecular weight (Mw) on a standard polystyrene basis, determined by GPC measurement, was 7200, and the molecular weight dispersion (Mw / Mn) was 1.55. １３ The copolymerization ratio (the proportion (molar ratio) of each constituent unit in the structural formula) determined by C-NMR was l / m = 60 / 40.

[0406] (A)-5: A polymer represented by chemical formula (A)-5. The weight-average molecular weight (Mw) on a standard polystyrene basis, determined by GPC measurement, was 7000, and the molecular weight dispersion (Mw / Mn) was 1.51. １３ The copolymerization ratio (the proportion (molar ratio) of each constituent unit in the structural formula) determined by C-NMR was l / m = 60 / 40.

[0407] (A)-6: A polymer represented by chemical formula (A)-6. The weight-average molecular weight (Mw) on a standard polystyrene basis, determined by GPC measurement, was 6900, and the molecular weight dispersion (Mw / Mn) was 1.50. １３ The copolymerization ratio (the proportion (molar ratio) of each constituent unit in the structural formula) determined by C-NMR was l / m = 60 / 40.

[0408]

[0409] (A)-7: A polymer represented by chemical formula (A)-7. The weight-average molecular weight (Mw) on a standard polystyrene basis, determined by GPC measurement, was 7500, and the molecular weight dispersion (Mw / Mn) was 1.57. １３ The copolymerization ratio (the proportion (molar ratio) of each constituent unit in the structural formula) determined by C-NMR was l / m = 60 / 40.

[0410] (A)-8: A polymer represented by chemical formula (A)-8. The weight-average molecular weight (Mw) on a standard polystyrene basis, determined by GPC measurement, was 6800, and the molecular weight dispersion (Mw / Mn) was 1.50. １３ The copolymerization ratio (the proportion (molar ratio) of each constituent unit in the structural formula) determined by C-NMR was l / m = 60 / 40.

[0411] (A)-9: A polymer represented by chemical formula (A)-9. The weight-average molecular weight (Mw) on a standard polystyrene basis, determined by GPC measurement, was 6500, and the molecular weight dispersion (Mw / Mn) was 1.53. １３ The copolymerization ratio (the proportion (molar ratio) of each constituent unit in the structural formula) determined by C-NMR was l / m = 60 / 40.

[0412]

[0413] (A)-10: A polymer represented by the chemical formula (A)-10. The weight-average molecular weight (Mw) on a standard polystyrene basis, determined by GPC measurement, was 7000, and the molecular weight dispersion (Mw / Mn) was 1.47. １３ The copolymerization ratio (the proportion (molar ratio) of each constituent unit in the structural formula) determined by C-NMR was l / m = 60 / 40.

[0414] (A)-11: A polymer represented by chemical formula (A)-11. The weight-average molecular weight (Mw) on a standard polystyrene basis, determined by GPC measurement, was 7100, and the molecular weight dispersion (Mw / Mn) was 1.51. １３ The copolymerization ratio (the proportion (molar ratio) of each constituent unit in the structural formula) determined by C-NMR was l / m = 60 / 40.

[0415]

[0416] (A)-12: A polymer represented by chemical formula (A)-12. The weight-average molecular weight (Mw) on a standard polystyrene basis, determined by GPC measurement, was 8800, and the molecular weight dispersion (Mw / Mn) was 1.63. １３ The copolymerization ratio (the proportion (molar ratio) of each constituent unit in the structural formula) determined by C-NMR was l / m / n = 58 / 28 / 14.

[0417] (A)-13: A polymer represented by chemical formula (A)-13. The weight-average molecular weight (Mw) on a standard polystyrene basis, determined by GPC measurement, was 9100, and the molecular weight dispersion (Mw / Mn) was 1.65. １３ The copolymerization ratio (the proportion (molar ratio) of each constituent unit in the structural formula) determined by C-NMR was l / m / n / o = 56 / 26 / 14 / 4.

[0418] <Preparation of Resist Compositions> (Examples 1-15, Comparative Examples 1-3) The resist compositions for each example were prepared by mixing and dissolving the components shown in Tables 1-2.

[0419]

[0420] In Table 1, each abbreviation has the following meaning. The numbers in brackets [ ] represent the amount used (parts by mass; on a solid content basis).

[0421] (A)-1 to (A)-13: The polymers (A)-1 to (A)-13 described above.

[0422] (A)-21: A polymer represented by the following chemical formula (A)-21. The weight-average molecular weight (Mw) on a standard polystyrene basis, determined by GPC measurement, was 7300, and the molecular weight dispersion (Mw / Mn) was 1.73. １３ The copolymerization ratio (molar ratio of each constituent unit in the structural formula) determined by C-NMR was l / m = 60 / 40. The brackets in chemical formula (A)-21 indicate the terminal structure of the polymer main chain.

[0423] (A)-22: A polymer represented by the following chemical formula (A)-22. The weight-average molecular weight (Mw) on a standard polystyrene basis, determined by GPC measurement, was 7000, and the molecular weight dispersion (Mw / Mn) was 1.75. １３ The copolymerization ratio (the proportion (molar ratio) of each constituent unit in the structural formula) determined by C-NMR was l / m / n = 55 / 35 / 10.

[0424] (A)-23: A polymer represented by the following chemical formula (A)-23. The weight-average molecular weight (Mw) on a standard polystyrene basis, determined by GPC measurement, was 3600, and the molecular weight dispersion (Mw / Mn) was 1.76. １３ The copolymerization ratio (the proportion (molar ratio) of each constituent unit in the structural formula) determined by C-NMR was l / m = 60 / 40.

[0425]

[0426] (B)-1: An acid generator consisting of the compound (B)-1 described below. (B)-2: An acid generator consisting of the compound (B)-2 described below.

[0427]

[0428] (D)-1: An acid diffusion control agent consisting of the compound (D)-1 described below. (D)-2: An acid diffusion control agent consisting of the compound (D)-2 described below.

[0429]

[0430] (S)-1: A mixed solvent of propylene glycol monomethyl ether acetate / propylene glycol monomethyl ether = 60 / 40 (mass ratio).

[0431] <Formation of Resist Pattern> Steps for forming the resist film: Each resist composition was applied to an 8-inch silicon substrate treated with hexamethyldisilazane (HMDS) using a spinner, and a pre-bake (PAB) treatment was performed on a hot plate at a temperature of 110°C for 60 seconds, followed by drying to form a resist film with a thickness of 50 nm.

[0432] Steps for exposing the resist film: Next, the resist film was exposed using an electron beam lithography system JEOL JBX-9300FS (manufactured by JEOL Ltd.) at an acceleration voltage of 100 kV, with a target size of a 1:1 line-and-space pattern (hereinafter referred to as "LS pattern") with a line width of 50 nm (pitch width of 100 nm). After that, a post-exposure heating (PEB) treatment was performed at 100°C for 60 seconds.

[0433] Steps for developing the resist film after exposure: Next, the exposed resist film was subjected to alkaline development at 23°C for 60 seconds using a 2.38% by mass aqueous solution of tetramethylammonium hydroxide (TMAH) "NMD-3" (trade name, manufactured by Tokyo Ohka Kogyo Co., Ltd.). After that, it was rinsed with pure water for 15 seconds. As a result, in all cases using the resist composition, a 1:1 LS pattern with a line width of 50 nm (pitch width of 100 nm) was formed.

[0434] [Evaluation of Optimal Exposure Dose (Eop)] The optimal exposure dose Eop (μC / cm²) when forming a target-sized LS pattern by the above <Formation of Resist Pattern> is determined. ２ The result was calculated as "Eop(μC / cm²)". ２ This is shown in Table 2.

[0435] [Evaluation of Line-Wide Roughness (LWR)] For the LS pattern formed by the above <Formation of Resist Pattern>, 3σ, a measure of LWR, was determined. The results are shown in Table 2 as "LWR (nm)". "3σ" represents three times the standard deviation (σ) (unit: nm) obtained from the measurement results of 400 line positions in the longitudinal direction of the line using a scanning electron microscope (acceleration voltage 800V, product name: S-9380, manufactured by Hitachi High-Technologies Corporation). A smaller value of 3σ means that the roughness of the line sidewall is smaller and a more uniform width LS pattern was obtained.

[0436] [Evaluation of film thinning] Film thinning was evaluated by measuring the film thickness of the large unexposed area after the PAB treatment in the <Formation of resist pattern> described above, and the film thickness after rinsing with water, and determining the rate of change in film thickness. The results are shown in Table 2 as "Residual film percentage (%)". A larger residual film percentage indicates a smaller rate of change in film thickness and that film thinning was suppressed.

[0437]

[0438] As shown in Table 2, the resist compositions of Examples 1 to 15 to which the present invention was applied were found to have higher sensitivity, reduced roughness, and to be able to form a good resist pattern with suppressed film loss, compared to the resist compositions of Comparative Examples 1 to 3.

[0439] Comparison of Examples 1-9 with Comparative Example 3: It can be confirmed that the resist compositions of Examples 1-9 have higher sensitivity, reduced roughness, and significantly suppressed film loss compared to the resist composition of Comparative Example 3.

[0440] The resist compositions of Examples 1 to 9 contain polymers (polymer (A)-1 to polymer (A)-9) in which a linking group represented by the general formula (a0-L) constitutes part of the polymer main chain and has a weight-average molecular weight (Mw) of 6500 to 7500. The resist composition of Comparative Example 3 contains a polymer (polymer (A)-23) with a weight-average molecular weight (Mw) of 3600. In the resist compositions of Examples 1 to 9, in the resist film exposure area, the linking group is divided into two by the action of the acid, causing the polymer main chain to decompose, reducing the Mw of the polymer and improving the solubility of the polymer in the developer (TMAH aqueous solution). The Mw of the polymer forming the unexposed area of ​​the resist film remains unchanged at 6500 to 7500, showing a high effect of inhibiting dissolution in the developer and a high residual film rate. Furthermore, before and after exposure, the Mw of the polymer forming the resist film differs between the exposed portion of the resist film where the decomposition of the linking groups occurs and the unexposed portion of the resist film where the decomposition of the linking groups does not occur, resulting in a large difference in dissolution contrast with the developer. On the other hand, in the resist composition of Comparative Example 3, no change occurs in the main chain of the polymer forming the exposed portion of the resist film, and the Mw of the polymer forming the unexposed portion of the resist film is 3600, resulting in a low dissolution inhibition effect with respect to the developer and a low residual film rate.

[0441] Although preferred embodiments of the present invention have been described above, the present invention is not limited to these embodiments. Additions, omissions, substitutions, and other modifications to the configuration are possible without departing from the spirit of the present invention. The present invention is not limited by the foregoing description and is limited only by the appended claims.

Claims

A resist composition that generates acid upon exposure and whose solubility in a developer changes due to the action of the acid, It contains a resin component (A1) whose solubility in the developer changes due to the action of acid, The resin component (A1) is a resist composition comprising a polymer (A1-0) in which a linking group represented by the following general formula (a0-L) constitutes part of the polymer main chain. [In the formula, R １０ R represents a hydrocarbon group whose linking group is split into two by the action of an acid. ２０ and R ３０ *1 and *2 each independently represent alkylene groups with 1 to 5 carbon atoms. *1 and *2 each represent bonds attached to the polymer main chain. O is an oxygen atom. S is a sulfur atom. In the above general formula (a0-L), R １０ The resist composition according to claim 1, wherein at least one of the -C(=O)-O- bonded carbon atoms (C*) is a hydrocarbon group in which a tertiary carbon atom is present, or the carbon atom (C*) is a hydrocarbon group in which a secondary carbon atom is present. 　 The polymer (A1-0) is a polymer compound in which a first copolymer is bonded to the bond side *1 and a second copolymer is bonded to the bond side *2 via the linking group. The resist composition according to claim 1, wherein the first copolymer and the second copolymer each contain a copolymer having a repeating structure of a constituent unit (a1) containing an acid-degradable group whose polarity increases upon the action of an acid, and a constituent unit (a10) represented by the following general formula (a10-1). [In the formula, R is an alkyl group having 1 to 5 carbon atoms, an alkyl halide having 1 to 5 carbon atoms, or a hydrogen atom. Ya ｘ１ This is a divalent linking group or a single bond. Wa ｘ１ n is an aromatic hydrocarbon group which may have substituents. ａｘ１ [ is an integer greater than or equal to 1.] 　 The resist composition according to claim 1, wherein the weight-average molecular weight of the polymer (A1-0) is 4,000 or more and 12,000 or less. 　 A method for forming a resist pattern, comprising the steps of: forming a resist film on a support using a resist composition according to any one of claims 1 to 4; exposing the resist film; and developing the exposed resist film to form a resist pattern. 　 A polymer in which a linking group represented by the following general formula (a0-L) constitutes part of the polymer main chain. [In the formula, R １０ represents a hydrocarbon group in which the linking group is divided into two by the action of an acid. R ２０ and R ３０ each independently represent an alkylene group having 1 to 5 carbon atoms. *1 and *2 each represent a bond that binds to the polymer main chain. O is an oxygen atom. S is a sulfur atom.] In the above general formula (a0-L), R １０ The polymer according to claim 6, wherein at least one of the -C(=O)-O- bonded carbon atoms (C*) is a hydrocarbon group in which a tertiary carbon atom is present, or the carbon atom (C*) is a hydrocarbon group in which a secondary carbon atom is present. 　 This polymer compound has a first copolymerized portion bonded to the bonded end *1 side and a second copolymerized portion bonded to the bonded end *2 side via the aforementioned linking group. The polymer according to claim 6, wherein the first copolymer and the second copolymer each comprise a copolymer having a repeating structure of a constituent unit (a1) containing an acid-degradable group whose polarity increases upon the action of an acid, and a constituent unit (a10) represented by the following general formula (a10-1). [In the formula, R is an alkyl group having 1 to 5 carbon atoms, an alkyl halide having 1 to 5 carbon atoms, or a hydrogen atom. Ya ｘ１ This is a divalent linking group or a single bond. Wa ｘ１ n is an aromatic hydrocarbon group which may have substituents. ａｘ１ [ is an integer greater than or equal to 1.] The polymer according to any one of claims 6 to 8, wherein the weight-average molecular weight is 4,000 or more and 12,000 or less.

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